Answer:
Upthrust = 20 N
Explanation:
The question says that "A body weighs 100N in air and 80N when submerged in water. Calculate the upthrust acting on the body ?"
Upthrust is defined as the force when a body is submerged in liquid, then liquid applies a force on it.
ATQ,
Weight of body in air is 100 N
Weight of body in water is 80 N
Upthrust is equal to the weight of body in air minus weight of body in water.
Upthrust = 100 N - 80 N
Upthrust = 20 N
So, 20 N of upthrust is acting on the body.
7. Two billiard balls of equal mass, one blue and the other red, slide towards each other at 2.0m/s in opposite
directions towards each other. They collide head on and rebound both at 1.8m/s in opposite to their original
velocities,a s shown in the diagram below. Show how momentum is conserved in this collision.
Answer:
P = M V expresses momentum
Both before and after collision the momenta are equal and in opposite directions. So the the total momentum is zero both before and after the collision. P is a vector quantity as is the velocity. Total momentum must be zero.
A train is moving along a horizontal track. A pendulum suspended from the roof makes an angle of 4° with the vertical. If g=10m/s2, what is the acceleration of the train?
Answer:
Train accaleration = 0.70 m/s^2
Explanation:
We have a pendulum (presumably simple in nature) in an accelerating train. As the train accelerates, the pendulum is going move in the opposite direction due to inertia. The force which causes this movement has the same accaleration as that of the train. This is the basis for the problem.
Start by setting up a free body diagram of all the forces in play: The gravitational force on the pendulum (mg), the force caused by the pendulum's inertial resistance to the train(F_i), and the resulting force of tension caused by the other two forces (F_r).
Next, set up your sum of forces equations/relationships. Note that the sum of vertical forces (y-direction) balance out and equal 0. While the horizontal forces add up to the total mass of the pendulum times it's accaleration; which, again, equals the train's accaleration.
After doing this, I would isolate the resulting force in the sum of vertical forces, substitute it into the horizontal force equation, and solve for the acceleration. The problem should reduce to show that the acceleration is proportional to the gravity times the tangent of the angle it makes.
I've attached my work, comment with any questions.
Side note: If you take this end result and solve for the angle, you'll see that no matter how fast the train accelerates, the pendulum will never reach a full 90°!
Pls help A car starts from rest and gains a velocity of 20m/s in 10 seconds calculate its acceleration and the distance covered by it in this time
Answer:
[tex] \boxed{\sf Acceleration \ (a) = 2 \ m/s^{2}} [/tex]
[tex] \boxed{\sf Distance \ covered \ (s) = 100 \ m} [/tex]
Given:
Initial velocity (u) = 0 m/s
Final velocity (v) = 20 m/s
Time taken (t) = 10 sec
To Find:
(i) Acceleration (a)
(ii) Distance covered (s)
Explanation:
[tex]\sf (i) \ From \ 1^{st} \ equation \ of \ motion:[/tex]
[tex] \sf \implies v = u + at[/tex]
[tex] \sf \implies 20 = 0 + a(10)[/tex]
[tex] \sf \implies 10a = 20[/tex]
[tex] \sf \implies \frac{10a}{10} = \frac{20}{10} [/tex]
[tex] \sf \implies a = 2 \: m/ {s}^{2} [/tex]
[tex]\sf (ii) \ From \ 2^{nd} \ equation \ of \ motion:[/tex]
[tex] \sf \implies s = ut + \frac{1}{2} a {t}^{2} [/tex]
[tex]\sf \implies s = (0)(10) + \frac{1}{2} \times 2 \times {(10)}^{2} [/tex]
[tex]\sf \implies s = \frac{1}{ \cancel{2}} \times \cancel{2} \times {(10)}^{2} [/tex]
[tex]\sf \implies s = {10}^{2} [/tex]
[tex]\sf \implies s = 100 \: m[/tex]
V = ?
d= 15 m left
t = 5 s
What is the velocity?
Answer:
Velocity= 3[tex]ms^{-1}[/tex]
Explanation:
Formula to find velocity = Displacement/time taken
therefore, velocity= 15/5 ➤ Velocity = 3 [tex]ms^{-1}[/tex]
which method is commonly used for improving cattle breeds and why?
Answer: Cross-breeding method is commonly used for improving cattle breeds. Cross-breeding between two good varieties of cattle will produce a new improved variety. Cross breeding is defined as the process or the act of producing offspring particularly through mating two pure bred individuals but come from different breeds, varieties, or even species. Crossbreeding is undertaken to: Utilise the desired attributes of two or more breeds. Produce progeny better suited to target markets while maintaining environmental adaption. Improve productivity quicker in traits which are slow to change within a breed i.e. environmental adaption, fertility and carcass traits.
Hope it helps :)
A rock is thrown at a window that is located 16.0 m above the ground. The rock is thrown from the ground at an angle of 40.0° above horizontal with an initial speed of 30.0 m/s and experiences no appreciable air resistance. If the rock strikes the window on its upward trajectory, from what horizontal distance from the window was it released?
Answer:
x = 27.3 m
Explanation:
This is a projectile launching exercise, let's start by looking for the time it takes for the rock to reach the height of the window.
Let's use trigonometry to find the velocities of the rock
sin 40 = [tex]v_{oy}[/tex] / v
cos 40 = v₀ₓ / v
v_{oy}= v sin 40
v₀ₓ = v cos 40
v_{oy} = 30 sin 40 = 19.28 m / s
v₀ₓ = v cos 40
v₀ₓ = 30 cos 40 = 22.98 m / s
we look for the time
[tex]v_{y}^2[/tex] = v_{oy}^2 - 2 g y
v_{y}^2 = 19.28 2 - 2 9.8 16 = 371.71 - 313.6 = 58.118
v_{y} = 7.623 m / s
we calculate the time
v_{y} = v_{oy} - gt
t = (v_{oy} - v_{y}) / g
t = (19.28 -7.623) / 9.8
t = 1,189 s
since the time is the same for both movements let's use this time to find the horizontal distance
x = v₀ₓ t
x = 22.98 1,189
x = 27.3 m
certain atom has 86 protons. Assume that the nucleus is a sphere with radius 6.98 fm and with the charge of the protons uniformly spread through the sphere. At the nucleus surface what are (a) the magnitude and (b) direction (radially inward or outward) of the electric field produced by the protons?
Answer:
a. [tex]2.54 \times 10^{21} NC^{-1}[/tex]
b. Outwards
Explanation:
The computation is shown below:
a. The magnitude could be computed by applying the following formula
Electric field, E is
[tex]= \frac{kq}{r^{2}} \\\\ = \frac{9\times10^{9} \times86\times1.6\times10^{-19}}{(6.98\times10^{-15})^2}[/tex]
[tex]= 2.54 \times 10^{21} NC^{-1}[/tex]
b. As we can see that there is a positive charge so the direction would be in the outward direction in the electric field i.e. produced by the protons
Basically we applied the above formula for the first part
An ideal gas is enclosed in a piston-cylinder apparatus with the piston being freely movable. Given that LaTeX: \DeltaΔE is positive and LaTeX: \DeltaΔH is negative following a process, ____ the system absorbs heat and expands during the process. the system absorbs heat and contracts during the process. the system loses heat and expands during the process. the system loses heat and contracts during the process. the system loses heat but neither expands nor contracts during the process.
Clear question is;
An ideal gas is enclosed in a piston-cylinder apparatus with the piston being freely movable. Given that ΔE is positive and ΔH is negative following a process,
pick one
A) the system absorbs heat and expands during the process.
B) the system absorbs heat and contracts during the process.
C) the system loses heat and expands during the process.
D) the system loses heat and contracts during the process.
E) the system loses heat but neither expands nor contracts during the process.
Answer:
Option A is correct.
Explanation:
In thermodynamics, when the change in energy which is ΔE of a system is positive, it means that the system is undergoing an endothermic process. An endothermic process is simply one where heat is absorbed from the surroundings
Now, when change in enthalpy which is ΔH is negative, it means that it's an exothermic reaction. Exothermic means it releases heat to the surroundings. This means work is positive because the system does work on the surroundings. Thus it will expand.
So the correct answer is;
heat is absorbed from the surroundings and will expand during the process.
what change in gravitational force become when mass of both bodies is double and distance between them is halved
Answer:
in such condition the gravitational force will increase 16 times
Please find attached photograph for your answer.
A rod is made up of copper and wood joined together.
After the rod is heated at the join in the centre for about a minute, where would the lowest temperature be?
my views
Explanation:
Figure (8) shows a rod made up of copper and wood joined together. The rod is heated at the joint in the centre for about a minute. At which point – A, B, C or D, would it show the lowest temperature? PLEASE GIVE REASONS ALSO(MINIMUM 2)
Why do scientists not use US customary units when reporting their data?
One of the scientist's jobs is to report the results of his experiments to all the other scientists in the world.
There isn't a single real science shop anywhere in the world that uses the US customary system of units. Not one.
Even in the measly three countries that use it for measuring carpet, pumping gas, and weighing fish ... Myanmar, Liberia, an the USA ... the scientists do their work in the SI/MKS/metric system.
Which has more mass, a 10 N object on the moon, or a 10 N object on the Earth?
Answer:
10N object on the earth
Gravity on moon is one sixth of earth
So a mass weighing 10N weighs 60N on earth .
So a 10N object on moon has more mass
A car is traveling to the right with a speed of 2.0\,\dfrac{\text m}{\text s}2.0 s m 2, point, 0, start fraction, start text, m, end text, divided by, start text, s, end text, end fraction on an icy road when the brakes are applied. The car slows down with constant acceleration for 3.0\,\text m3.0m3, point, 0, start text, m, end text until it comes to a stop. How long does it take the car to slide to a stop?
Answer:
It took the car 3 second to come to full stop
Explanation:
When the car is driving to the right at a speed of 2 m/s, and suddenly brakes giving the car a constant negative acceleration making it travel 3 meters after it stops, we can use the following kinematic equation to solve for the acceleration applied by the brakes:
[tex]v=v_0-a\,t\\0=2-a\,t\\a=\frac{2}{t}[/tex]
and we use this result in the following kinematic equation for the distance traveled to find the time it took it to stop:
[tex]x-x_0=v_0\,t-\frac{1}{2} a\,\,t^2\\3=2\,t -\frac{1}{2} (\frac{2}{t}) \,\,t^2\\3=2\,t-t\\3=t[/tex]
therefore, it took the car 3 seconds to come to a full stop.
Write the dirference between sl system
and cgs system
Explanation:
st system:the internationak system of measurement which i declared form internationäl convention of scientists held in france in 1960AD is Si system
CGS System:it measure in length in centimeter mass in gram time in second
A 310 turn solenoid with a length of 18.0 cm and a radius of 1.60 cm carries a current of 1.90 A. A second coil of four turns is wrapped tightly around this solenoid, so it can be considered to have the same radius as the solenoid. The current in the 310 turn solenoid increases steadily to 5.00 A in 0.900 s.(a) Use Ampere's law to calculate the initial magnetic field in the middle of the 310 turn solenoid.T(b) Calculate the magnetic field of the 310 turn solenoid after 0.900 s.T(c) Calculate the area of the 4-turn coil.m2(d) Calculate the change in the magnetic flux through the 4-turn coil during the same period.Wb(e) Calculate the average induced emf in the 4-turn coil.VIs it equal to the instantaneous induced emf? Explain.(f) Why could contributions to the magnetic field by the current in the 4-turn coil be neglected in this calculation?
Answer:
Given that;
Number of turns in the solenoid N = 310
Length of the solenoid L = 18 cm = 0.18 m
Radius of the solenoid r = 1.60 cm = 0.016 m
Current in the first Circuit I₁ = 1.90A
Number of turns in second coil N₂ = 4
Final Current solenoid I₂ = 5.0 A
Time interval to change the time Δt = 0.9 s
a)
According to Ampere's law, magnetic field inside a conductor is calculated as;
B₁ = ц₀N₁I₁ / L
(ц₀ = 4π × 10⁻⁷ constant)
therefore we substitute
{(4π × 10⁻⁷) × 310 × 1.9A} / 0.18m
= 0.0041 T
b)
Magnetic field inside the solenoid after t = 0.9
B₁ = ц₀N₁I₂ / L
= {(4π × 10⁻⁷) × 310 × 5.0A} / 0.18m
= 0.0108 T
c)
Area of coil is
A = πr²
A = π × ( 0.016 )²
A = 0.000804 m²
d)
Change in magnetic influx is
dФ = (B₂ - B₁) A
= ( 0.0108 T - 0.0041 T) × 0.000804 m²
= 0.0000053868 ≈ 5.39 × 10⁻⁶
e)
Average induced emf is
e = -N₂ ( dФ / dt )
e = ( -4 ) ( 5.39 × 10⁻⁶ / 0.9)
e = - 2.39 × 10⁻⁵V ( NOTE, this is not equal to the instantaneous induced emf )
f)
The induced emf is very low, so the contributions to the magnetic field in the coil is Negative.
An astronaut is said to be weightlessness when he\she travels in a satellite. Does it mean that the earth does not attract him\her?
Answer:
Explanation:
The sense of weightlessness in orbiting satellite is because of the lack of any contact-forces. ... Thus, both the astronaut and the satellite have the same value of g, which is again equal to the centripetal acceleration of the satellite. These two neutralize each other, causing everything to appear weightless.
MAKE ME BRAINLIEST
A 9V battery produces a 1.5A current in a piece of wire. What is the resistance of the wire?
8 Ω
9 Ω
6 Ω
7 Ω
Explanation:
Using Ohm's Law and a bit of substitution, we can use voltage divided by current to solve for resistance. Doing that, we'll get 6 Ohm.
If the mass of a ball is 50g on a height of 8m. Calculate the kinetic energy when it has a velocity of 3m/s.
Answer:
kinetic energy is 1/2mv^2.
which is 1/2×0.05×3^2
1/2×0.05×9.
1/2×0.45=
0.45÷2=0.225~0.23J
Help!!! Line B touches the circle at a single point. Line A extends through the center of the circle.
I. What is line b in reference to the circle?
2. How large is the angle between lines A and B?
Answer:
If I understand correctly. Line B is parallel to the circle. Also, the angle is less than 90.
The size of the circle determines. The diameter should not be fixed either.'Circle' is characterized as "a two-dimensional geometric figure comprising of the set of all those points in a plane that are at equal distance from the center."
1). Line B would be considered as the 'tangent' in association with the given circle.
2). The angle lying among the lines A and B would be of 90° i.e. right angle.
Given that,
A circle with line A drawn through its center
Line B moves while touching the edge of the circle and intersects line A outside the circle.
Since 'Tangent' is described as a 'straight-line touching the curve at one point without crossing it,' thus, line B would be considered as the tangent of the circle as it touches the circle's curve once. The angle that is formed at the intersection of the line A and B at the curve of the circle would be a right angle because they are perpendicular to one another. Thus, the perpendicular lines A and B form an angle of 90°.Learn more about 'circle' here:
brainly.com/question/11833983
Dr. Bishop wants to study how small children respond to scary stimuli. She will explain the procedure to parents and ask them to sign a permission form. She will have 3-5 year old kids individually come into her lab
Each child will be given a teddy bear to cuddle with. She will then stand a couple of feet behind the child as he or she plays and make a very loud scary sound. She will observe and measure the child's responses. The
child will come back in a few days and be given the teddy bear again, she will measure any reactions the child has to the bear.
What might an ethics review committee decide about the proposal?
The proposal is approved, as it meets the ethical guidelines defined by the APA
O The proposal is approved, because there is no deception
The proposal is denied, because participants wil ikely suffer psychological harm.
O The proposal is denied, because participants are not allowed to leave the study
The proposal is denied, because it does not meet confidentiality standards
Answer:
The correct option is;
The proposal is denied, because participants will likely suffer psychological harm
Explanation:
Among the recommendations in the report on ethical research with children, it is suggested that the following should be observed by researchers;
1) Seeking consent should be a continuous process
2) Contemplate payment forms other than money to allow more discretion on child safety
3) Have two way communication with the child
4) Ask for assent of the child participating in the research
The above APA suggestions where not met by the researcher in the study.
Answer:
The proposal is denied, because participants will likely suffer psychological harm.
Explanation:
This proposal would cause psychological harm to its participents.
I also took the test and that was the correct answer.
the speed of pendulum is slowest: a) at mountain b) at sea level
Answer:
At sea level
Explanation:
Because there is higher air pressure
A negative charge feels a force when stationary in an electric field. moving parallel to an electric field. moving parallel to a magnetic field. moving perpendicular to a magnetic field. stationary in a magnetic field. moving perpendicular to an electric field.
Answer:
stationary in an electric field.
moving perpendicular to a magnetic field.
moving perpendicular to an electric field.
Explanation:
Negative charge: In physics, the term "negative charge" is defined as a phenomenon that consists of a surplus or different electrons in any field i.e magnetic or electric field.
However, the correct answer in the question above, would be:
"stationary in an electric field".
"moving perpendicular to a magnetic field".
"moving perpendicular to an electric field".
Q1 b name the three tiny particles which make up atoms ? a write the charge alongside each one ?
Answer:
Protons
Neutrons
Electrons.
Protons + charge(positively charged)
Neurons no charge.
Electrons - ( negatively charged).
Explanation:
Atom is the smallest unit of a matter that constitutes chemical elements.
It is composed of three particles which are protons,neutrons and electrons.
Protons is positively charged,neuron has no charge and electrons is negatively charged.
Proton and neuron are found in the nucleus while electron is found outside the neuron.
The cartesian coordinates of a point in the xy plane are x = −7.11 m, y = −4.41 m. Find the distance r from the point to the origin. Answer in units of m.
Explanation:
Use Pythagorean theorem:
r² = x² + y²
r² = (-7.11 m)² + (-4.41 m)²
r = 8.37 m
Use trig to find the angle.
tan θ = y / x
tan θ = (-4.41 m) / (-7.11 m)
θ = 31.8° or 211.8°
Since x is negative and y is negative, the point is in the third quadrant, so θ = 211.8°.
Or, if we subtract 360°, θ = -148.2°.
the value of g is more in the poles of the earth,why?
Answer:
Explanation:
beacuse the poles are the cause of graIt's due to the rotation of earth about its own axis. Due to the rotation, objects placed on the surface of earth also rotates . Their rotational kinetic energy prevents them from the free fall along gravitational pull. This phenomena can also be explained sitting on the earth surface as their free fall suffers a centrifugal barrier due to the rotation. In this explanation, the term, centrifugal barrier, appears because earth is a non-inertial frame. Centrifugal force in a non intertial frame acts opposite to gravitational force.
The rotational energy / centrifugal barrier on a object depends on the radius of the circle linearly ; the circle is drawn around the axis of rotation from the point where the object placed. Now you can imagine that its radius get shorter and shorter towards the pole from the equator. Hence the barrier decreases if we move from equator to the both poles of earth. Hence garvitational force on a object i.e. its weight, so the g, becomes effectively maximum on the poles and minimum on the equator.
How has the games changed over the years?
Answer:
The definition of the particular circumstance consists provided in the subsection on the interpretation elsewhere here.
Explanation:
Throughout the past 10-20 years, the computer games industry is experiencing some insane shifts. Several of the adjustments are responsible for the observed market developments, while others are related to just the tech boom as well as technological development across the global economy. Here is another glimpse at some instances of how and why the gaming industry has evolved in just the last few decades.what is the Ramsar convention?
An eletric pump in the ground floor
building taken 15 then to fill
a tank of volume 300
3003 with water
If the tank in 40met above the ground
and the efficiency of the pump
not
find the electric power consumed by
the pump in filling
the tank
Answer:
The input power is [tex]44.4\times10^{3}\ kW[/tex]
Explanation:
Given that,
Time = 15 min
Volume of water = 30 m³
Height = 40 m
Efficiency = 30%
Density of water = 1000 kg/m³
Suppose, acceleration due to gravity = 10 m/s²
We need to calculate the mass of water pumped
Using formula of mass
[tex]Mass = Volume\times density[/tex]
Put the value into the formula
[tex]Mass=30\times1000[/tex]
[tex]Mass=3\times10^{4}\ kg[/tex]
We need to calculate the output power
Using formula of power
[tex]P_{out}=\dfrac{W}{t}[/tex]
[tex]P_{out}=\dfrac{mgh}{t}[/tex]
Put the value into the formula
[tex]P_{out}=\dfrac{3\times10^{4}\times10\times40}{15\times60}[/tex]
[tex]P_{out}=\dfrac{4}{3}\times10^{4}\ Watt[/tex]
We need to calculate the input power
Using formula of efficiency
[tex]\eta=\dfrac{P_{out}}{P_{in}}[/tex]
[tex]P_{in}=\dfrac{P_{out}}{\eta}[/tex]
Put the value into the formula
[tex]P_{in}=\dfrac{4\times100\times10^{4}}{3\times30}[/tex]
[tex]P_{in}=\dfrac{4\times10^{5}}{9}\ Watt[/tex]
[tex]P_{in}=44.4\times10^{3}\ kW[/tex]
Hence, The input power is [tex]44.4\times10^{3}\ kW[/tex]
Solve the following numerical problems. a) A load of 400N is lifted up by an effort of 100N. If load distance is 20cm, what will be the effort distance? (Ans: 80cm) b) Two boys, Shrijan having weight 600N and Shrijesh having weight 300N are playing see-saw. If Shrijan is sitting at 2m from fulcrum, where should Shrijesh sit from fulcrum to balance Shrijan?(Ans: 4m) c) A lever of length 1m has been used ttoko lift a load of 600N by applying an effort of 200N. If load is at 20cm from fulcrum, calculate mechanical advantage, velocity ratio and efficiency. (Ans: MA = 3, VR = 4, n=75%) d) Study the figure below and find the value of effort. (Ans: 120N) Muyn) 2.5m 600N 0.5m ? Science and Enyin
Answer:
given,
load = 400 N
effort = 100 N
load distance = 20 cm
we know that ,
E*Ed = L*Ld
=100 N* Ed = 400N * 20 cm
=100N * Ed = 8000N/cm
= Ed =( 8000N/cm ) / 100N
= Ed = 80 cm
b. soln.
given,
load = 600 N
load distance = 2 m
effort = 300 N
effort distance = ?
we know that ,
= E *Ed = L * Ld
= 300N * Ed = 600N * 2 m
= 300N * Ed = 1200N/m
=Ed =( 1200N/m ) / 300 N
= Ed = 4 m
C. soln.
given,
load = 600 N
load distance =20 cm
effort = 200 N
effort distance = ?
M.A = ?
V.R = ?
Efficiency = ?
we know that ,
= E *Ed = L *Ld
= 200N * Ed = 600 N * 20 cm
=200 N *Ed = 12000 N/cm
=Ed = ( 12000 N/cm) / 200 N
= Ed = 60 cm
Also,
M.A = load / effort
=600 N / 200 N
= 3
V.R = Ed/ Ld
= 60 cm / 20 cm
= 4
efficiency = ( M.A / V.R ) 100 %
= ( 3 / 4 ) 100%
= 75 %
d. soln.
given,
load = 600 N
load distance = 0.5 m
effort distance = 2.5 m
effort = ?
we know that ,
= E * Ed = L * Ld
= E * 2.5 m = 600 N * 0.5 m
= E * 2.5 m = 300 N / m
= E = ( 300 N / m ) / 2.5 m
= E = 120 N
Bus starts from rest if the acceleration of the bus is 0.5 MS square what will be the velocity at the end of two minutes and what distance will it cover during that time
Answer:
1. 60 m/s.
2. 3600 m.
Explanation:
The following data were obtained from the question:
Initial velocity (u) = 0
Acceleration (a) = 0.5 m/s²
Time (t) = 2 mins
Final Velocity (v) =?
Distance travelled (s) =?
1. Determination of the velocity at the end of 2 minutes.
Initial velocity (u) = 0
Acceleration (a) = 0.5 m/s²
Time (t) = 2 mins = 2 x 60 = 120 secs
Final Velocity (v) =?
v = u + at
v = 0 + (0.5 x 120)
v = 60 m/s
Therefore, the velocity at the end of 2 minutes is 60 m/s.
2. Determination of the distance travelled.
Initial velocity (u) = 0
Acceleration (a) = 0.5 m/s²
Final velocity (v) = 60 m/s
Distance travelled (s) =..?
v² = u² + 2as
60² = 0 + 2 x 0.5 x s
3600 = 1 x s
s = 3600 m
Therefore, the distance travelled is 3600 m.