A 3.0 g latex balloon is filled with 2.8 g of helium. When filled, the balloon is a 32-cm-diameter sphere. When released, the balloon accelerates upward until it reaches a terminal speed. What is this speed? Assume an air density of 1.2 kg/m3 and a drag coefficient for sphere of 0.47.
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The Venus-Sun distance is 108 million kilometers, and the Earth-Sun distance is 150 million kilometers. Suppose an imaginary line from Venus to the Sun forms a right angle with an imaginary line from Earth to the Sun. How long would it take light to travel from the Sun to a spaceship halfway along the straight-line path between Venus and Earth? The time is in minutes.
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A 60.0 kg person running at an initial speed of 4.50 m/s jumps onto a 120 kg cart that is initially at rest. The person slides on the cart's top surface and finally comes to rest relative to the cart. The coefficient of kinetic friction between the person and the cart is 0.320. Friction between the cart and the ground can be neglected.
a.Find the final speed of the person and cart relative to the ground.
b.For how long does the frictional force act on the person?
c.Determine the magnitude of the displacement of the person relative to the ground while he is slipping on the cart.
d. Determine the magnitude of the displacement of the cart relative to the ground while the person is slipping on the cart.
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1) what is a diffraction grating
2) why do we use "discharge tube" to perform the experiment instead of a light bulb
3)If "d " is the grating constant (spacing in between two slits on a grating), hoe can we obtain the ruling (number of grooves per meter) "D"?
4) Define " order of diffraction" and illustrate it using a drawing
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Discuss the motion of a cannonball shot at an angle in the sky. Is there an optimal angle that would increase the range of the cannonball shot?
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In a nuclear reactor, in the fission process, neutrons are emitted at high energies. Neutrons are to be thermalized, i.e., their kinetic energies have to be significantly reduced, so that you can increase the probability for the new fission processes. You have a choice of a number of materials such as, say, heavy, water, iron and lead. The neutrons experience elastic collisions with the atoms of these materials and lose their energies. Assuming the target atoms are at rest initially, out of the three materials given about which one would you prefer for the efficient thermalization of neutrons? Give reasons and explanation
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To transfer a fix amount of electrical energy while keeping Ohmic heating low, it is good to increase voltage？
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In an old-fashioned amusement park ride, passengers stand inside a 5.0-m-diameter hollow steel cylinder with their backs against the wall. The cylinder begins to rotate about a vertical axis. Then the floor on which the passengers are standing suddenly drops away! If all goes well, the passengers will "stick" to the wall and not slide. Clothing has a static coefficient of friction against steel in the range 0.62 to 1.0 and a kinetic coefficient in the range 0.40 to 0.70. A sign next to the entrance says "No children under 30 kg allowed."
Q: What is the minimum angular speed, in rpm, for which the ride is safe?
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An object's weight is W0 on the earth.
a. What would be its weight (in terms of W0) if the earth had twice its present mass, but was the same size?
b.What would be its weight (in terms of W0) if the earth had half its present radius, but the same mass?
c. What would be its weight (in terms of W0) if the earth had half its present radius and half its present mass?
d.What would be its weight (in terms of W0) if the earth had twice its present radius and twice its present mass?
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How can I find the force of a laser given wavelength and power? Is it just momentum or momentum multiplied by number of phtons or something else?
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Problem 1: For all of the following problems, imagine a crane that is lifting a weight of mass m through a height h at constant speed, and consider the following three choices of system:
(1) system is the weight only; (2) system is the weight and the earth; (3) system is the crane only.
For each of these choices, and in this order, what is the net work done on the system by the external forces (Wext,sys) in the process considered?
(a) (1) 0; (2) mgh; (3) −mgh
(b) (1) mgh; (2) 0; (3) −mgh
(c) (1) −mgh; (2) mgh; (3) 0
(d) (1) 0; (2) mgh; (3) 0
Problem 2: For system (1) (weight only), which of the following is a correct statement of the energy changes going on inside the system during the process described?
(a) ∆Esource + ∆Ediss = −mgh
(b) ∆U G = mgh
(c) ∆K = 0
(d) ∆Ediss = mgh
Problem 3: For system (2) (weight and earth), which of the following is a correct statement of the energy changes going on inside the system during the process described?
(a) ∆Esource + ∆Ediss = −mgh
(b) ∆U G = mgh
(c) ∆K = 0
(d) ∆Ediss = mgh
Problem 4: For system (3) (crane only), which of the following is a correct statement of the energy changes going on inside the system during the process described?
(a) ∆Esource + ∆Ediss = −mgh
(b) ∆U G = mgh
(c) ∆K = 0
(d) ∆Ediss = mgh
Problem 5: If it takes a time ∆t to raise the weight through the height h, what is the power output of the crane for that process?
(a) mg (b) mgh (c) mgh/∆t (d) 0
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A projectile is launched with speed v0 and angle θ. Derive an expression for the projectile's maximum height h.
A baseball is hit with a speed of 35.0 m/s . Calculate its height if it is hit at an angle of 30.0 ∘ .
A baseball is hit with a speed of 35.0 m/s . Calculate its distance traveled if it is hit at an angle of 30.0 ∘ .
A baseball is hit with a speed of 35.0 m/s . Calculate its height if it is hit at an angle of 45.0 ∘ .
A baseball is hit with a speed of 35.0 m/s . Calculate its distance traveled if it is hit at an angle of 45.0 ∘ .
A baseball is hit with a speed of 35.0 m/s . Calculate its height if it is hit at an angle of 60.0 ∘ .
A baseball is hit with a speed of 35.0 m/s . Calculate its distance traveled if it is hit at an angle of 60.0 ∘ .
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A heat engine operates between two reservoirs at T2 = 600 K and T1 = 350 K. It takes in 1 000 J of energy from the higher-temperature reservoir and performs 250 J of work. Find (a) the entropy change of the Universe delta SU for this process and (b) the work W that could have been done by an ideal Carnot engine operating between these two reservoirs. (c) Show that the difference between the amounts of work done in parts (a) and (b) is T1 delta SU .
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A particle undergoes a constant acceleration of 4.00 m/s2. After a certain amount of time, its velocity is 12.2 m/s. (Where applicable, indicate the direction with the sign of your answer.) (a) If its initial velocity is 6.1 m/s, what is its displacement during this time? m (b) What distance does it travel during this time? m (c) If its initial velocity is −6.1 m/s, what is its displacement during this time? m (d) What is the total distance the particle travels during the interval in part (c)? m
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True or False
Heat Travels slower in air than in liquids or solids.
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