Answer:
S = v0 t + 1/2 a t^2 a = 0 seems given in the problem
Vp t = Vr t + 16
both travel for time t but the police car is going faster and travels 16 km farther
t (Vp - Vr) = 16
t = 16 km / (100 - 80) km/hr
t = 16 / 20 hr = 4/5 hr = 48 min
How much heat does it take to melt a 0.234 kg ice cube at its melting point?
Answer:
Q = M kg* 3.33E5 J / kg = .234 * 3.33E5 = 7.79E4 Joules
As a check (using 80 cal/gm as latent heat of fusion for water)
234 g * 80 cal/gm = 18720 cal
1 cal = 4.19 J
18720 cal * 4.19 J / cal = 7.7E4 J agrees with value found above
A golf club exerts an average force of 500N on a 0.1kg golf ball and the contact time is 0.01s.
What is the change in velocity of the golf ball?
Answer:
[tex]50\; {\rm m\cdot s^{-1}}[/tex], assuming that the force on the golf ball was constant.
Explanation:
Assume that the force the golf club exerted on the golf ball a constant force of magnitude [tex]F[/tex]. Let [tex]\Delta t[/tex] denote the duration the club was in contact with the golf ball. The impulse of this force would be:
[tex]J = F\, \Delta t[/tex].
Let [tex]\Delta p[/tex] denote the change in the momentum of this golf ball. By the impulse-momentum theorem, this [tex]\Delta p\![/tex] would be equal to the impulse on the golf ball.
[tex]\Delta p = J = F\, \Delta t[/tex].
The momentum [tex]p[/tex] of this golf ball is the scalar product between the mass [tex]m[/tex] of this golf ball and the velocity [tex]v[/tex] of this golf ball. The mass of this golf ball stays the same. Thus, when the momentum of this golf ball changes by [tex]\Delta p[/tex], the velocity of this golf ball would change by [tex](\Delta p) / (m)[/tex].
The change in the velocity of this golf ball would thus be:
[tex]\begin{aligned}\Delta v &= \frac{\Delta p}{m} & \genfrac{}{}{0em}{}{(\text{change in momentum})}{}\\ &= \frac{J}{m} & \genfrac{}{}{0em}{}{(\text{impulse on the golf ball})}{}\\ &= \frac{F\, \Delta t}{m} \\ &= \frac{500\; {\rm N} \times 0.01\; {\rm s}}{0.1\; {\rm kg}} \\ &\approx 50\; {\rm m\cdot s^{-1}}\end{aligned}[/tex].
(Note that [tex]1\; {\rm N} = 1\; {\rm kg \cdot m^{2}\cdot s^{-2}}[/tex].)
Applying definitions Samantha ran 90 meters in 35 seconds to catch up with her dog. When she got to him, she played with him for 70 seconds before they walked back in 75 seconds. Did Saman tha travel at constant speed? What was Samantha's average speed?
No, Saman didn't travel at constant speed
v₁ = 90/35 = 2.57 m/s
v₂ = 0
v₃ = 90/75 = 1.2 m/s
Average speed = total distance/time
Average speed = (90+90)/(35+70+75) = 1 m/s
Cause and Effect Reasoning Quick Check
1. Cells can repair small amounts of damage. In what situation-
[Answer: A person is exposed to large amounts of gamma rays.]
2. If a certain amount of time in the sun is dangerous for adults, what could-
[Answer: The adult and child would get the same damage per]
3. An individual must receive quite a lot of sun exposure over time to develop a high risk of cell damage. [Answer: A shorter exposure time to X-rays gives the same risk]
4. Ultraviolet light can damage a cell. Which exposure would most likely-
[Answer: 5 minutes of exposure to UVB light]
5. New vaccine studies are sometimes tested on pigs.
[Answer: Humans have an immune system very similar to pigs.]
The principle of cause and effect is applied in every life as is seen in damage caused to cells by exposure to large amounts of ultravoilet rays.
What is cause and effect?Cause and effect refers to the principle in which for every effect received or observed, an underlying cause is present.
Based on cause and effect;
Cells can repair small amounts of damage caused when a person is exposed to large amounts of gamma rays.
If a certain amount of exposure time in the sun is dangerous for adults, would result in a similar damage to a child.
A lot of sun exposure over time will cause an individual to develop a high risk of cell damage just as a shorter exposure time to X-rays gives the same risk.
Ultraviolet light can damage a cell especially with over 5 minutes of exposure to UVB light.
New vaccine studies are sometimes tested on pigs because humans have an immune system very similar to pigs.
Therefore, cause and effect is applied in every activities.
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When 20. joules of work are done in 4.0 seconds; what is the power developed?
A. 0.20 watt
B. 5.0 watts
C. 16 watts
D. 80. watts
the power developed when, 20 joules of work are done in 4.0 second.
solution:power= workdone/ time
here workdone= 20 joules
time taken= 4.0s
so putting these values in the above formula, we get:
power= 20/4.0
=5.0 watts
answer= option b) 5.0 watts
[tex]\bold\blue{Formula : }[/tex]
[tex]\bold{Power = \frac{energy}{time} }[/tex]
[tex]\bold\blue{Given : }[/tex]
Joules of work = 20 work are done = 4.0 seconds[tex]\bold\blue{ Solution : }[/tex]
[tex]\bold{Power = \frac{energy}{time} }[/tex]
[tex]\bold{Power = \frac{20}{4.0} }[/tex]
[tex] \bold{ Power = 5.0}[/tex]
So , B.) 5.0 watts is answer .
If the same object was taken to each of the planets, where would it weigh the most and where would it weigh the least
Answer:
it way the most on jupiter and the least on mars
Explanation:
While electric current is flowing through a wire, what surrounds the wire?.
A material that doesn't conduct electricity well - such as a plastic/rubber covering, acting as the electrical insulator.
Hope this helps!
where are metamorphic rocks formed? And how are they formed
6th Grade Earth science
Answer:
Metamorphic rocks form when rocks are subjected to high heat, high pressure, hot mineral-rich fluids or, more commonly, some combination of these factors. Conditions like these are found deep within the Earth or where tectonic plates meet.
How are temperature and molecular motion related?
Answer:
temperature is essentially the speed of the molecules.
Explanation:
temperature is the kinetic energy of molecules, and kinetic energy is dependent on velocity.
a doctor measures the temperature of a patient to be 101 degrees . what is this temperature in kelvins
Answer:
the answer is 374.15 kelvins
If our planet was twice as far away how would the Earth’s orbit change?
Answer:
One of the indirect proofs that orbits change is actually in the growth of our own teeth when we were children. our teeth are some of the most basic, and primitive
parts of our bodies. They grow on a 9 day cycle, which was an ancient full moon to full moon cycle when the Earth and the Moon were a lot smaller, and closer together, and the co-orbital period was only 9 days, not the 29.5 days that it is currently.
So Given any two " Planets " that co-orbit a common gravitational center, the larger planet will grow larger far faster than the smaller planet, and the larger planet will accelerate the smaller planet to a higher orbit with a longer period, and decelerate itself to a lower orbit with a longer period, and the absolute value of the center to center distance will increase, and the orbital period will increase. The two orbs and their common gravitational center will remain co-linear through out the gradual growing and changing process.
This is an important process for the enlargement of the solar system as time passes, and an important process for larger galaxies as they attract and merge with smaller galaxies.
All of the planets grow larger at an accelerating rate, and thus systems spiral outward concentrating mass into larger and fewer galaxies, solar systems, and planet - moon systems.
The downward motion of an elevator is controlled by a cable that unwinds from a cylinder of radius 0.20 m. what is he angular velocity of the cylinder when the downward speed of the elevator is 1.2 m/s
The angular velcoity of this cylinder when the downward speed of the elevator is 1.2 m/s would be 6 rad/s.
Given the following data:
Radius of cylinder = 0.20 meter.
Linear velocity = 1.2 m/s.
What is angular velocity?Angular velocity can be defined as the rate of change of angular displacement of an object with respect to time. Thus, it is a measure of how fast and quickly an object revolves or rotates relative to another point or how its angular position changes with respect to time.
The formula for angular velcoity.Mathematically, angular velcoity is given by this formula:
[tex]V =r\omega\\\\\omega =\frac{V}{r}[/tex]
Substituting the given parameters into the formula, we have;
[tex]\omega = \frac{1.2}{0.2}[/tex]
Angular velocity = 6 rad/s.
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As an ambulance siren passes and moves away from you, the sound waves'
frequency __________
and their amplitude ________
A. increases,
decreases
B. increases,
increases
C. decreases,
increases
D. decreases,
decreases
[tex]\qquad\qquad\huge\underline{{\sf Answer}}♨[/tex]
Amplitude and frequency are two properties of sound waves that decreases as distance from source decrease.
Therefore, as the ambulance moves away,
frequency - decreasesamplitude - decreasesSo, correct choice is D
An ideal single movable pulley requires an input force that is one-half the ouput force.
True False
While on the surface of the earth a student has a weight of 450n if she is moved twice as far from the center of the earth then how does the new weight compare to her old?
Based on the fact that the student is moved twice as far from the center of the earth, her new weight will be 112.5 N.
What is her new weight?When the student was moved by the same distance from the center of the earth, her weight was halved.
When she was then moved twice as far, her weight was halved again.
This means that her new weight is:
= 450 x 1/2 x 1/2
= 450 x 1/4
= 112.5 N.
Find out more on weight at https://brainly.com/question/2537310.
why do we use dry cell in torch light ?
Answer:
The three reasons for this is because of high enrgy density, self-discharge, and small amount of energy.
Explanation:
These are why that happens.
Hope this helps!
-Justin
A spaceship moves at a constant velocity of 0.400c relative to an Earth observer. The pilot of the spaceship is holding a rod, which he measures to be 1.00 m long. The rod is held perpendicular to the direction of motion of the spaceship. How long is the rod according to the Earth observer
Since the rod is held perpendicular to the direction of motion of the spaceship, the rod is 1.00 m long to an Earth observer.
To answer the question, we use the principle of length contraction in relativity.
What is Length contraction?The principle of length contraction states that the length of an object would only contraction when it is in the direction of motion.
So, since the 1.00 m long rod is in the spaceship is held perpendicular to the direction of motion of the spaceship, there is no length contraction and thus, an observer on the Earth measures the same length of 1.00 m.
So, Since the rod is held perpendicular to the direction of motion of the spaceship, the rod is 1.00 m long to an Earth observer.
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You catch a 219 g ball moving at 6.1 m/s. If you catch the ball in a time period of
0.138 s what is the magnitude of the average force you must supply to the ball to
stop the ball?
Answer in units of Newtons (N)
Answer:
The magnitude of the average force to supply to the ball in order to stop the ball is 9.68 N.
Explanation:
Let's think Newton's 2nd Law: F = ma.
We are given the mass of the ball: 219 g ⇒ .219 kg.
We are given the initial velocity, time, and final velocity of the ball ∴ we can solve for acceleration.
We are trying to find the force needed to stop the ball.
Let's find the acceleration of the ball first.
We have the initial velocity of the ball, 6.1 m/s.We have the time it would hypothetically take the ball to stop, .138 s.We have the final velocity of the ball, 0 m/s (since we are trying to stop the ball).Now, we can plug these known values into this kinematic equation and solve for acceleration, a.
v = v₀ + at 0 = 6.1 + a(.138) -6.1 = .138a a = 44.2029 m/s²Substitute acceleration and mass into F = ma and solve for the force.
F = (.219)(44.2029) F = 9.68 NThe magnitude of the average force to supply to the ball in order to stop the ball is 9.68 N.
16. Pressure of a fluid depends upon:
a) Height of the object
b) Depth at which object moves
c) density of the medium
d) all of above
Answer:
b that is density at object moves
Which of these invertebrates have asymmetric bodies?
Answer:
Sponges
Explanation:
It would be either sponges or flatworms.
I apologize if it is incorrect-
I hope it helps! Have a great day!
Anygays-
A particle moves in the xy plane in a circle centered on the origin. at a certain instant the velocity and acceleration of the particle are 6. 0 m/s and (3. 0 + 4. 0) m/s2. what are the x and y coordinates of the particle at this moment?
The x and y coordinates of the particle at this moment is (6x + 4.5y) m.
Position of the particleThe position of the particle at any instant is determined from the velocity and acceleration of the particle as shown below.
v² = u² + 2as
where;
v is the final velocity of the particleu is the initial velocitya is the acceleration of the particles is the position of the particlev² = 0 + 2as
v² = 2as
s = v²/2a
X and y - coordinates of the particle[tex]s_x = \frac{v^2}{2a_x} = \frac{6^2}{2(3)} = 6\ m\\\\s_y = \frac{v^2}{2a_y} = \frac{6^2}{2(4)} = 4.5 \ m\\\\s = (6 x \ + 4.5y)m[/tex]
Thus, the x and y coordinates of the particle at this moment is (6x + 4.5y) m.
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What was the first car fitted with an alternator, rather than a direct current dynamo?.
Answer:
The first vehicles fitted with an alternator was vehicles during WWll.
Chrysler Corporation fitted an alternator on the Valiant 1960 as standard equipment
Explanation:
Answer:
The first car fitted with an alternator, rather than a direct current dynamo was the 1960 Plymouth Valiant.
Which planet, other than earth, has visible water ice on it?.
You need to move a large refrigerator. It has a mass of 300 kg. You want to accelerate it at a rate of 3 m/s/s. What force must you apply?
Answer:
900 N
Explanation:
F = ma
= 300 (3) = 900 N
a 20-kg object travelling at 20 m/s collides head on with an 18-kg object travelling at 17 m/s.If they were locked together after the collision, what is their velocity?.
Answer:
2.47 m/s
Explanation:
Momentum = Mass X Velocity
If they were locked together, it means its a perfectly inelastic collision. Therefore,
Total momentum before = Total momentum after
Total momentum before = (20 X 20) - (18 X 17)
= 94
Total momentum after = 94
Y = Object speed after collision
94 = (20+18)Y
Y = 2.47368421 m/s
Hello people ~
Question: A hemisphere is uniformely charged positively. The electric field a point on a diameter away from the centre is directed
(a) perpendicular to the diameter
(b) parallel to the diameter
(c) at an angle tilted towards the diameter
(d) at an angle tilted away from the diameter
As the electric field is present at a point on diameter the electric field intensity at the electric field components are parallel to the diameter hence they cancel out .
So the field is directed perpendicular towards the diameter
Option A
What will an atom do if it has 1 to 3 valence electrons?
move electrons to a lower shell
move electrons to a higher shell
accepts (gains) electrons
donates (loses) electrons
Answer:
donates (loses) electrons
Explanation:
Atoms are most stable when they have zero valence electrons (full octets) and have the same electron configuration as the Noble Gases.
Atoms that have 1-3 valence electrons are most likely to donate them to reach this stable configuration.
An example is Sodium (Na) has 1 valence electron, as it is group one of the periodic table, and it often forms as a positive cation (Na+1) by donating its valence electron.
What is the volume of one rubber ball? round to the nearest hundredth of a centimeter. cm3 if the price of the rubber needed to produce a ball is $0.0045/cm3, what is the cost of producing one ball? round to the nearest cent. $ if the company sells a ball for $0.50, how much profit will it make on each ball? $
The volume of one rubber ball and the cost of producing one ball and the profit will it make on each ball will be 20.58 cm³, $0.09261, and $0.40739 respectively.
What exactly is geometry?It is concerned with the geometry, region, and density of various 2D and 3D shapes.
The given data in the problem is;
r is the Rubber balls = 1.7 cm
V is the volume
C is the cost of production
P is the profit
The volume of the rubber ball is found as;
[tex]\rm v= \frac{4}{3} \pi r^3 \\\\ \rm v= \frac{4}{3} \times 3.14 (4.913)^3 \\\\ \rm v= 20.58 cm^3[/tex]
If the price of the rubber required to make a ball is $0.0045/cm3, the ball's production cost will be $0.0045/cm3.
The cost of a ball is the multiplication of the cost of one ball and the selling price of the ball;
C = 0.0045 x 20.58
C = $0.09261
P is the profit gained and profit is the subtraction of the selling price and cost price.
P = S.P.-C.P.
P=0.5 - 0.09261
P = $0.40739
Hence the volume of one rubber ball and the cost of producing one ball and the profit will it make on each ball will be 20.58 cm³, $0.09261, and $0.40739 respectively.
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Answer:
1: C
2: C
3: A
Explanation: just did it
A sound travels down a hallway that is 115 m long. Then it echoes and
returns back to the source. If the speed of sound is 350 m/s, how long
does it take in seconds) to hear the echo?
Answer:
0.66 s
Explanation:
∆x = v∆t → 2 × 115 = 350 ∆t → ∆t = 230/350 = 0.66 s
Sally and Suzy are moving into their first college dorm together. They are loading all their furniture onto a truck with a ramp that is 8 feet long.
How far is the back of the truck off the ground if the mecanical advantage of this ramp is 2?
A) .25 ft
B) 4 ft
C) 8 ft
D) 16 ft
Answer:
B
Explanation:
Formula
Mechanical advantage = length of the ramp / height
Givens
Length of the ramp = 8
Mechanical advantage = 2
height = ?
Solution
2 = 8feet / height Multiply both sides by height
2* height = 8 feet * height / height Combine
2* height = 8 feet Divide by 2
2*height/2 = 8 feet/2
height = 4 feet.