AP PHYSICS 1 SOME FINAL EXAM PRACTICE PROBLEMS

  1. A spaceship travels from earth to a distant star 14.5 light years away at a speed of 0.90 c. How much time will elapse for observers on Earth? How much time will elapse for observers on the spaceship? Which observer measures the distance to be 14.5 light years? How far would the other observer say the trip was?
  1. A projectile is fired with an initial speed of 65.2 m/s at an angle of 34.5º above the horizontal on a long flat firing rang. Determine the maximum height reached by the projectile, the total time in the air, the total horizontal distance covered, and the velocity of the projectile 1.5 s after firing.
  1. Given the circuit shown, determine,

  1. The equivalent resistance
  2. The voltage across the 680 Ω resistor
  3. The rate at which energy is produced in the battery.
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  1. A block of mass 2.7 kg sits on a rough ramp (μk = 0.15) which is inclined at 25º. A rope attached to the box (and parallel to the plane) passes over a pulley at the top of the ramp and connects the block to another 2.7 kg block which hangs vertically. The hanging block will fall (thus pulling the block on the incline up the incline). What is the acceleration of the blocks?
  1. A train traveling at a constant speed rounds a curve of radius 235 m. A lamp suspended from the ceiling swings out to an angle of 17.5º throughout the curve. What is the speed of the train?
  1. Calculate the electric field at one corner of a square 1 m on a side if the other three corners are occupied by 2.25 µC charges.
  1. A helicopter is ascending vertically with a speed of 5.2 m/s. At a height of 125 m above the Earth, a package is dropped from a window. How much time does it take for the package to reach the ground?
  1. A guitar string is 90 cm long and has a mass of 3.6 g. The distance from the bridge to the support post is 62 cm, and the string is under a tension of 520 N. What are the frequencies of the fundamental mode and first two overtones?
  1. The work done by an external force to move a -8.5 μC charge from point A to point B is 15 x 10-4 J. If the charge was started from rest and had 4.82 x 10-4 J of kinetic energy when it reached point B, what must be the potential difference between A and B? Which point is at higher potential?
  1. The wiring in a house must be thick enough so it does not become so hot as to start a fire. What diameter must a copper wire be if it is to carry a maximum current of 35 A and produce no more than 1.8 W of heat per meter of length?
  1. An airplane pilot fell 370 m after jumping from an aircraft without his parachute opening. He landed in a snowbank, creating a crater 1.1 m deep, but survived with only minor injuries. Assuming the pilot’s mass was 78 kg and his terminal velocity was 35 m/s, estimate the work done by the snow in bringing him to rest, the average force exerted on him by the snow to stop him, and the work done on him by air resistance as he fell.
  1. When violet light of wavelength 415 nm falls on a single slit, it creates a central diffraction peak that is 9.20 cm wide on a screen that is 2.55 m away. How wide is the slit?
  1. A 920 kg sports car collides into the rear end of a 2300 kg SUV stopped at a red light. The bumpers lock, the brakes are locked, and the two cars skid forward 2.8 m before stopping. The police officer, knowing that the coefficient of kinetic friction between tires and road is 0.80, calculates the speed of the sports car at impact. What was that speed?
  1. A uniform meter stick with a mass of 180 g is supported horizontally by two vertical strings, one at the 0 cm mark and the other at the 90 cm mark. What is the tension in the string at 0 cm? At 90 cm?
  1. A tennis ball of mass 0.06 kg and speed 20 m/s strikes a wall at a 38 angle to the wall and rebounds with the same speed at 38 to the wall. What is the impulse given to the wall?
  1. How far above the surface of the Earth will the acceleration due to gravity be one half of its value on the surface?
  1. A tuning fork is held vibrating over a tube filled to the brim with water. As the water level is lowered, the sound is loud when the air column is 18.5 cm long and 57.1 cm, but nowhere in between. Assuming a room temperature of 20 °C, find the frequency of the tuning fork. If this were the fundamental frequency of an open-ended tube, how long would the tube be?
  1. A 0.5 kg mass is suspended by a massless string that passes over a frictionless pulley (which is suspended by the ceiling) and is attached to a 0.3 kg mass on the other side. The mass of the pulley is 2.5 kg, and its radius is 10 cm; it is a uniform disk. What is the magnitude of the acceleration of the masses? What is the rotational speed of the pulley when the masses are moving at 3 m/s?
  1. A -4 µC charge is placed at the origin, and a +10 µC charge is placed at x = -12 cm. Where on the x-axis is the electric field equal to zero? Where on the x-axis is the electric potential equal to zero?

Answers:

  1. 16.1 years, 7.02years, observers on earth, 6.32 light years.
  2. 69.5 m, 7.53 s, 405 m, 58.1 m/s at 22.4°
  3. 842 Ω, 5.31 V, 0.17 W
  4. 2.2 m/s2
  5. 26.9 m/s
  6. 3.88 x 104 N/C away from the center of the square (along the diagonal)
  7. 5.6 seconds
  8. 291 Hz, 582 Hz, 873 Hz
  9. -120 V, A
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  1. 3.8 mm
  2. -49 kJ, 4.4 x 104 N, -235 kJ
  3. 23 μm
  4. 23.2 m/s
  5. 0.78 N, 0.98 N
  6. 1.48 Ns (toward the wall)
  7. 2.64 x 106 m
  8. 444 Hz, 38.6 cm
  9. 0.96 m/s2, 30 rad/s
  10. E=0 at x= 20.6 cm; V=0 at x= -3.43 cm and x = 8 cm