(a)One end of a string is attached to a wall and the
other end is attached to a mass sitting on a ramp tilted at an
angle of 35 degrees. It takes a pulse 10 ms to travel the length of
the 1 m string. The string has a mass 1.5 g. What is the mass that
is attached to the string?
(b) The string is replaced by two strings that are
knotted together, L1 has a length 60 cm and L2 has a length of 40
cm. They have a linear mass density of of mu1 =
1.4 x 10-4 kg/m and mu2 = 2.8 x
10-4 kg/m. Like before, they are attached to the
mass you found in part a. A pulse is sent from each end of the
string. Which pulse meets the knot first?
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Suppose I pour 13.5 mL of creamer into 159 mL of hot coffee. The creamer is at 43.4 deg F, and the coffee is at 188 deg F. What is the final temperature when the system reaches equilibrium, in deg F? Assume coffee and creamer have the same density and thermal properties of water.
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Three people talk simultaneously. If the intensity level is 92 dB when either one speaks alone, what is the intensity level when both speak at once?
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Two converging lenses are separated by 29.00 cm. The focal length of each lens is 17.00 cm. An object is placed 32.00 cm to the left of the lens that is on the left. Determine the final image distance relative to the lens on the right.
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5 kg of saturated liquid water at 10 bars is contained in a piston-cylinder assembly and undergoes two processes. process 1-2: heated at constant pressure until it is saturated vapor. process 2-3: cooled as it is compressed at constant volume until it reaches 110 degrees celsius. determine the overall work and heat transfer for these processes. Hint: Must used linear interpolation from values in the correct Water tables.
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Projectile Motion: If you launch projectile horizontally and drop a stone at the same time from the same height, which one will strike the ground first. Explain why. Assume no air resistance. (Hint: they actually will hit the ground at the same time. HMMM... why?)
Projectile Motion: If you launch a cannon at 15 degrees above horizontal, and another cannon at 75 degrees above horizontal, which one will reach farther horizontal range? Explain your answer.
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you have a toy car running on two batteries. if you could hook it up wit only one of the batteries, it would draw
a)twice as much current as the two batteries
b) half as much current as the two batteries
c) the same amount of current as the two batteries
why??
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A fullback with a mass of 116 kg and a velocity of 2.7 m/s due
west collides head-on with a defensive back with a mass of 89 kg
and a velocity of 6 m/s due east.
(a) What is the magnitude of the fullback's initial momentum?
(b) What is the direction of the fullback's initial momentum?
(c) What is the magnitude of the defensive back's initial
momentum?
(d) What is the direction of the defensive back's initial
momentum?
(e) What is the magnitude of the total momentum of the
system?
(f) If they stick together and external forces can be ignored, what
direction will they be traveling immediately after they
collide?
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Using Maxwell's equations and the variety of forms, how do you think that such a wave can self-propogate without a constant source of radiation?
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Helmholtz coils are frequently used in experiments because they create a uniform magnetic field about their central axis. For example, they are traditionally used in the experiment for the measurement of the charge‑to‑mass ratio of the electron. Helmholtz coils are two coils separated by a distance equal to their radius and also carry equal currents in the same direction, as shown in the figure. Suppose the radius of the coils is ?=16.50 cm R=16.50 cm and each coil carries a current of ?=15.50 AI=15.50 A and has ?=500.0 turns.N=500.0 turns. The coils are in the ??yz plane where one coil's center is at ?=0 x=0 the other coil's center is at ?=?.x=R.
Using the Biot–Savart law, determine the expression for the resultant magnetic field ??Bx along the line ?x joining their centers. Express the magnetic field in terms of the radius of the coils ?,R, the number of turns ?,N, the current ?,I, ?,x, and the permeability of free space, ?0.
Bx= ?
Evaluate the magnetic field ??Bx at ?=4.125 cm x=4.125 cm (14?)(14R) and ?=12.38 cm x=12.38 cm (34?).
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Based on what you heard in this podcast, do you think you are "frying your brain" with your cell phone? Why or why not?
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A man of mass 80 kg runs up a flight of stairs 20 m high in 10 s. (a) how much power is used to lift the man? (b) If the man’s body is 25% efficient, how much power does he expend? (c) This man consumes approximately 1.05 × 107 J (2500 food calories) of energy per day while maintaining a constant weight. What is the average power he produces over a day? (d) Compare this with his power production when he runs up the stairs.
Answer is: a) 1.6 kW; (b) 6.3 kW; (c) 122 W; (d) 1.9% of power produced running up stairs
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Two cars start from rest at a red stop light. When the light turns green, both cars accelerate forward. The blue car accelerates uniformly at a rate of 3.6 m/s2 for 4.4 seconds. It then continues at a constant speed for 8.2 seconds, before applying the brakes such that the car
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Find the electric field at the location of qa in the figure below, given that qb = qc = qd = +1.85 nC, q = ?1.00 nC, and the square is 11.5 cm on a side. (The +x axis is directed to the right.)
| magnitude |
N/C |
| direction |
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