Answer:
165.529454
Explanation:
According to the Pythagorean Theorem for calculating the lengths of a right angle triangle's sides, a^2 + b+2 = c^2, where c is the longest side (and the side opposing the right angle). So in your case it would be 150*150 + 70*70 = 27400. And √ 27400 is your answer.
The robot HooRU is lost in space, floating around aimlessly, and radiates heat into the depths of the cosmos at the rate of 13.5 W. HooRU's surface area is 1.51 m^2 and the emissivity of its surface is 0.209. Ignore the radiation HooRU absorbs from the cold universe. What is HooRU's temperature?
Answer:
165.73 K
Explanation:
The computation of HooRU's temperature is shown below:-
As per the stefan's law, the power radiated by black body radiations which is
[tex]P = eA\sigma T^4[/tex]
where
A indicates surface area
e indicates emissitivity
T indicates temperature
now, we will put the values in the above equation
[tex]13.5 = 0.209 \times 1.51 \times \sigma \times T^4[/tex]
After solving the above equation we will get temperature which results
= 165.73 K
Therefore for computing the HooRU's temperature we simply applied the above formula.
Q. A train accelerates from 36 km/h to 54 km/h in 10 sec. (i) Acceleration (ii) The distance travelled by car.
u=10m/s
v=15m/s
acceleration=
v_u/ t
5/10
0.5
Suppose the maximum safe intensity of microwaves for human exposure is taken to be 1.00 W/m2. (a) If a radar unit leaks 50.0 W of microwaves (other than those sent by its antenna) uniformly in all directions, how far away (in cm) must you be to be exposed to an intensity considered to be safe
Answer:
The safe distance is 199 cm approximately 200 cm
Explanation:
Safe intensity = 1.00 W/m^2
wattage of radar leaked radar = 50.0 W
safe distance from the microwave will be = ?
We know that the intensity of a wave radiated uniformly in all direction is given as
[tex]I[/tex] = [tex]\frac{W}{A}[/tex]
where
W is the wattage of the leaked radar
A is the radial area, which is the area of a sphere that encapsulates the region through which this wave spreads uniformly.
From the equation above,
[tex]A[/tex] = [tex]\frac{W}{I}[/tex] = 50/1 = 50 m^2
But the area of this sphere [tex]A[/tex] = [tex]4\pi r^{2}[/tex]
where
r is the safe distance from the radar source
substituting for the area, we have
50 = 4 x 3.142 x [tex]r^{2}[/tex]
50 = 12.568 [tex]r^{2}[/tex]
[tex]r^{2}[/tex] = 50/12.568 = 3.978
r = [tex]\sqrt{3.978}[/tex] = 1.99 m = 199 cm ≅ 200 cm
A rocket is launched vertically from the ground with an initial velocity of 64. Write a quadratic function that shows the height, in feet, of the rocket t seconds after it was launched.
Answer:
y = 64t − 16t²
Explanation:
y = y₀ + v₀ t + ½ at²
y = 0 + 64 t + ½ (-32) t²
y = 64t − 16t²
A polonium isotope with an atomic mass of 211.988868 u undergoes alpha decay, resulting in a daughter isotope with an atomic mass of 207.976652 u. Ignoring any recoil of the daughter, find the kinetic energy of the emitted alpha particle in megaelectronvolts (MeV).
Answer:
K = 9.53 MeV
Explanation:
The kinetic energy that the alpha particle has emitted, is the energy in excess after removing the resting energy of the atoms and the helium nucleus that forms the alpha particle
Since energy and masses are related and cannot be
m₀ c² = [tex]m_{f}[/tex] c² + m_He c²+ K
K = c² (m₀ - m_{f} - m_He)
the mass of the Helium atom is 4 u
K = (3 10⁸)² (211,988868 -207.976652 - 4,002) 1,661 10⁻²⁷
K = 14,949 10⁻¹¹ (0.0102)
K = 1,527 10⁻¹² J
let's reduce 1 J = 6,242 10¹² MeV
K = 9.53 MeV
A ball is dropped from a height of 20m. If its velocity increases uniformly at the rate 10m/s2 with what velocity and after what time will it strike the ground?
Answer: 2 seconds
Explanation:
Since I've only memorized a couple of formulas for these things, I need to do the time first:
I'll use the formula Distance = (1/2) (acceleration) (time)²
20 m = (1/2) (10 m/s²) (time)²
Time² = (20 m) / (5 m/s²)
Time² = 4 sec²
Time = 2 seconds
Now ...
-- When the ball hits the ground, it has been falling for 2 seconds.
-- Its acceleration has caused its speed to increase by 10 m/s every second.
-- So after 2 seconds, its speed has grown to (2 s) (10 m/s²) = 20 m/s .
Suppose a current-carrying wire has a cross-sectional area that gradually becomes smaller along the wire, so that the wire has the shape of a very long,truncated cone. How does the drift speed vary along the wire?
Answer:
It slows down as the cross-section becomes smaller is the correct answer to this question.
Explanation:
That current is the same in all parts of the wire under steady-state conditions.Thus the velocity of drift is approximately equal to the cross‐sectional region.vd = I /nAq . As the cross-section gets smaller it accelerates.3. An electron with a mass of 9.11 X 10^-31 kg is moving at a speed of 2.19 X 10 m/s. What is the kinetic energy of the electron?
Answer:
[tex] 2.18\times 10^{-30} \:J[/tex]
Explanation:
[tex] K.E._{Electron}= \frac{1}{2} mv^2 \\\\
= \frac{1}{2} \times 9.11\times 10^{-31}\times (2.19\times 10)^2 \\\\
=4.555\times 10^{-31}\times 4.7961\times 10^2 \\\\
=4.555\times 10^{-31+2}\times 4.7961 \\\\
=21.8462355\times 10^{-29}\\
=2.18462355\times 10^{-30}\\
=2.18\times 10^{-30} \:J\\[/tex]
Which force is there between an ice skate and the ice
Tech A says that an overdrive gear ratio means the input gear turns faster than the output gear. Tech B says that overdrive ratios provide less torque output than underdrive ratios. Who is correct?
Answer:
Technician B only is correct
Explanation:
The gear ratio is the ratio of the output speed to the input speed such that an overdrive gear ratio of more than 1:1, having more speed per speed of engine rotation RPM
Overdrive ratios conditions is one where the vehicle wheels and speed is faster at a given engine rotation, such that there is fuel efficiency is increased as the engine rotation is low for a given speed and distance of travel.
PLEASE HELP!!!! i will give brainliest to the first person...
Answer: Fossil fuels power the machine that shakes the tree so the apples fall to the ground
Explanation: most machines are powered by fossil fuels
Signal propagation in the nervous system can be modeled as
a) A resistor network.
b) A wave of electricity that travels down conducting tissue.
c) A series of RC circuits.
Answer:
c) A series of RC circuits.
Thurst exerted by an object of area20m² experiencing pressure 150 Nm‐² is ________
Answer:
3000 N
Explanation:
as we know that
pressure=force/area
so force=thurst
pressure=thurst/area
thyrst=pressure*area
pressure=150 Nm^-2
area=20m^2
so thurst=150*20=3000 N or 3*10^3 N
2. A solid sphere and a solid cylinder, both uniform and of the same mass and radius, roll without slipping at the same forward speed. It is correct to say that the total kinetic energy of the solid sphere is A) more than the total kinetic energy of the cylinder. B) less than the total kinetic energy of the cylinder. C) equal to the total kinetic energy of the cylinder.
Select the type of energy involved in each step. You turn on the burner of a gas stove. The gas ignites. The gas warms the water in the pan.
Answer:
You turn on the burner of a gas or stove - mechanical energy.
The gas ignites - Chemical energy.
The gas warms the water in the pan - Thermal energy.
Neglecting air resistance, the distance s(t) in feet traveled by a freely falling object is given by the function s(t)=16t2, where t is time in seconds. The height of a certain tower is 840 feet. How long would it take an object to fall to the ground from the top of the building?
Answer:
t=7.25 sec
Explanation:
840=16t'2,
List the submultiples and multiple units of length, mass, and time with respect to real-life situations. How are these units are related to S I unit of the above mentioned physical quantity?
Answer:
Explanation:
In physics, there are two types of physical quantities namely the fundamental and the derived quantities. Fundamental quantities are independent quantities on which derived quantities depends on. Length, mass and time are examples of fundamental quantities.
The SI unit of length is meters. A meter is a multiple unit. Its submultiple units are centimetres (10⁻²metres), kilometres (10³metres), decimetres (10⁻¹metres) etc
The SI unit of mass is kilogram (kg). The only sub multiple unit used in real-life situation is grams.
1 kg = 100 grams
The SI unit of time is seconds. The multiple units are the minutes, hours, weeks, days and years.
1 minute = 60 seconds
1 hour = 3600 seconds
1 day = 24 * 3600 = 86,400 secs
If you could travel from one planet to another
in our solar system, which of the following
would change the most?
A. your weight
B. your mass
C. your height
D. your width
Which of these are scientific questions? Check all that apply. How will climate change affect forests? Which planet is the prettiest? How did life on Earth begin? Why did dinosaurs go extinct? Which volcano is the most amazing?
Answer:
The scientific questions here are:
a) How will climate change affect forests
b) How did life on Earth begin
c) Why did dinosaurs go extinct
Explanation:
Scientific question are logical quantifiable questions, whose answers can be measured. A good scientific question must have answers that can be tested by a carefully designed experiment or measurement. Some qualities like "prettiest" and "amazing" cannot be tested for nor are they measurable, and hence, they do not make a testable component of good scientific question.
The water tank is kept at some height of the buildings. Why?
Answer:
The water is at the top because when the water is stored at the top it does not need as much energy to get it to flow because it will be flowing down and be affected by gravity to make the water pressure.
Answer:
The water is at the top because when the water is stored at the top it does not need as much energy to get it to flow because it will be flowing down and be affected by gravity to make the water pressure.
Explanation:
You are observing the radiation from a distant active galaxy and you notice that the amplitude of the signal varies in strength regularly over a certain period. The maximum possible size for the source of this radiation can now be calculated from the:____________
Answer:
Period of the signal.
Explanation:
So, this question is all about a concept in physics or astronomy which is called or known as Radiation Astronomy and Galactic Nuclei that are active. This concept talks most about Quasars; a powerful radiating object which derives its power from black holes.
When You take a look at Quasars, we get the to know that the more you think you can see, the more they move away from us.
Thus, when "You are observing the radiation from a distant active galaxy and you notice that the amplitude of the signal varies in strength regularly over a certain period. The maximum possible size for the source of this radiation can now be calculated from the "PERIOD OF THE SIGNAL.
NB: not the amplitude but the period.
If three cars, each of mass 1000 kg , occupy the NE, SE, and SW corners, determine the coordinates of the CM of the loaded ferryboat relative to the center of the raft. Take the origin to be at the CM of the raft.
Answer:
Using X = sum( x's * mass)/sum( masses)
= [(0)*(6400)+ (-9.5*1000) + (9.5)*(1000) + (9.5)*(1000)]/(6400+1000+1000+1000)
= 1.01 m
Y = sum( y's * mass)/sum( masses)
= [(0)*(6400) + (9.5)*(1000) +(-9.5)*(1000) + (-9.5)*(1000)]/ (6400+1000+1000+1000)
= -1.01 m
Determine whether or not each of the following statements is true. If a statement is true, prove it. If a statement is false, provide a counterexample and explain how it constitutes a counter-example.
A capacitor consists of two flat, metal plates with unequal areas. Each of the plates starts neutral, and then each plate is connected to a dierent terminal of a battery. After some time, the plates will have excess charge on them, and the magnitude of the excess charge on one plate will equal the magnitude of the excess charge on the other plate.
A. True
B. False
If a wire carries current, then it has a net non-zero charge in it.
A. True
B. False
Answer:
a) True b) True
Explanation:
a) a capacitor is made up of two flat plates and each one has a charge of the same sign, therefore the statement is true
b) the current is the flow of electrons per unit of time, therefore the charge is not zero, therefore the statement is True
Two runners start at a distance of 10 miles from each other. They run towards each other at a constant velocity of 5 mph. A fly takes off from runner one’s nose at time zero. The fly has a constant velocity of 20 mph and flies between the runners. Find the total distance that the fly has traveled when the runners collide.
Answer:
The fly will travel 20 miles before the runners collide with each other.
Explanation:
Since the runners are both traveling at the same speed, they will meet and collide in the exact middle of each other which is 5 miles away from their starting point. Since they are traveling at 5 mph, it will take exactly one hour before they collide. The fly is going 20 mph so it will travel 20 miles before the runners collide in one hour.
(a) Two microwave frequencies are authorized for use in microwave ovens: 900 and 2560 MHz. Calculate the wavelength of each. (b) Which frequency would produce smaller hot spots in foods due to interference effects
Answer:
a) wavelength for the two frequencies are 0.33 m and 0.12 m
(b) 2560 MHz
Explanation:
Given:
microwave frequencies are
900 and 2560 MHz
f1= 900MHz we need to convert it to Go so the unit will be able to be consistent
f1= 900MHz= 900× 10^6Hz
f2= 2560 MHz= 2560×10^6Hz
a)Calculate the wavelength of each
But we can calculate our wavelength λ using the below formula
λ=c/f
c which is the speed of light has a constant value of =3*10^8m/s
Then for the first frequency
λ=c/f =(3×10^8)/900×10^6
=0.33 m
=33 cm.
For the second frequency
λ=c/f = (3×10^8)/2560×10^6
=0.12 m
=12 cm
(b) Which frequency would produce smaller hot spots in foods due to interference effects
(b) 2560 MHz( has the smallest wavelength)
This is because a small wavelength microwave gives a pattern with which is interference with waves and have a closer hotspot
On his fishing trip Justin rides in a boat 12 km south. The fish aren’t biting so they go 4 km west. They then follow a school of fish 1 km north. What distance did they cover? What was their displacement?
Answer:
I think the answer is 8km2
Answer:
Distance = 17km
Displacement = 12.6 km
Explanation:
south 12km
west 4km
north 1km
Total distance = 12 + 4 + 1 = 17km
Total displacement = in picture above.
A vertical bar consists of three prismatic segments A1, A2, and A3 with cross-sectional areas of 6000 mm2 , 5000 mm2 , and 4000 mm2 , respectively. The bar is made of steel with E 5 200 GPa. Calculate the displacements at points B, D
Answer and Explanation:
For computing the displacement at point B and D we need to determine the following calculations
[tex]P_Net = P_C + P_E + P_B[/tex]
= 250 + 350 - 50
= 550 N
Now the deflection for bar AB is
[tex]\delta_{AB} = \frac{PL_{AB}}{AE} \\\\ = \frac{550 \times 500}{6,000 \times 200 \times 10^{3}}[/tex]
[tex]= 2.292 \times 10^{-4} mm[/tex]Now for bar BC it is
[tex]\delta_{BC} = \frac{PL_{BC}}{AE} \\\\ = \frac{(550 + 50) \times 250}{5,000 \times 200 \times 10^{3}} \\\\ = 1.5 \times 10^{-04} mm[/tex]
And for bar CD it is
[tex]\delta_{CD} = \frac{PL_{CD}}{AE} \\\\ = \frac{(550 -250 + 50) \times 250}{5,000 \times 200 \times 10^{3}} \\\\ = 0.875 \times 10^{-4} mm[/tex]
Now the displacement is as follows
For B
2.292 × 10^{-4} mm
For D, it is
[tex]= 2.292 \times 10^{-4} + 1.5 \times 10^{-4} + 0.875 \times 10^{-4} mm \\\\ = 4.667 \times 10^{-4} mm[/tex]
We simply applied the above formulas for determining the displacements at points B, D and the same is to be considered
Which of the following is a TRUE
statement about states of matter?
A. Most matter on Earth exists as a solid, liquid, or gas.
B. Plasma, the fourth state of matter, is abundant on Earth.
C. Matter never changes from a solid to a liquid or a gas.
D. Most matter in the universe is liquid.
The statement that is the most true regarding the states of matter is the first statement.
A. Most matter on Earth exists as a solid, liquid, or gas.
This is correct since most of the matter on Earth exists in those 3 states, meanwhile plasma is not a state that most of matter on earth is found in since it is mostly associated to stars and the external galactic regions.
Therefore, B is incorrect.
C is false, since almost of all of the matter on earth can transform and change through each of the 3 states of matter, solid, liquid, and gas.
D is false since most of the matter in universe is actually made out of plasma instead of a liquid. In fact, over 99% of the known universe's matter is said to consist of plasma.
Matter can be defined as the material substance which constitutes the observable nature. Most matter on Earth exists as a solid, liquid, or gas. Plasma is also the state of matter found in daily life. The correct option is A.
What are states of matter?All the materials which we see in our daily lives are made up of matter. Matter can be classified into different states such as solid, liquid and gas based on the intermolecular forces and the arrangement of particles. All the three states of matter can be converted from one form to another.
The molecules of solid are tightly packed and they have strong intermolecular forces which also has a definite shape and volume. The liquids have weak intermolecular forces than the solids and it acquire the shape of the vessel.
The intermolecular forces in gases are negligible and they do not have any fixed shape or volume.
Thus the correct option is A.
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A rocket moves through empty space in a straight line with constant speed. It is very far from any star or planet. Under these conditions, the force that must be applied to the rocket in order to sustain its motion is
Answer:
analysis the force is zero
Explanation:
Let's apply Newton's second law
F = m a
In this equation we see that the force is directly related to the acceleration, as they indicate that the rocket is far from any planet or star has no force applied to it, therefore they also relate it to zero.
Change we can analyze the exercise with Newton's first law, which indicates that an object maintains its constant speed in a straight line has no forces applied to it.
In either analysis the force is zero
Earthquakes at fault lines in Earth's crust create seismic waves, which are longitudinal (P-waves) or transverse (S-waves). The P-waves have a speed of about 9 km/s. Estimate the average bulk modulus of Earth's crust given that the density of rock is about 2500 kg/m3
Answer:
[tex]B=2.025\times 10^{11}\ Pa[/tex]
Explanation:
It is given that,
Speed of P- waves, v = 9 km/s = 9000 m/s
The density of rock is about [tex]2500\ kg/m^3[/tex]
We need to find the average bulk modulus of Earth's crust. Let it is given by B. So,
[tex]v=\sqrt{\dfrac{B}{d}} \\\\B=v^2d\\\\B=(9000)^2\times 2500\\\\B=2.025\times 10^{11}\ Pa[/tex]
So, the bulk modulus of the Earth's crust is [tex]2.025\times 10^{11}\ Pa[/tex].