Exam 2: Describing Motion: Kinematics in One Dimension

A test rocket at ground level is fired straight up from rest with a net upward acceleration of 20 m/s². After 4.0 s, the motor turns off but the rocket continues to coast upward with insignificant air Resistance. What maximum elevation does the rocket reach?

A battery charges a parallel-plate capacitor fully and then is removed. The plates are then slowly pulled apart. What happens to the potential difference between the plates as they are being Separated?

A sonic boom occurs only as an airplane just reaches the speed of sound in air, but not after it increases its speed further.

A solid aluminum cube rests on a wooden table in a region where a uniform external electric field is directed straight upward. What can we say concerning the charge on the top surface of the Cube?

When a current flows through a metal wire, the moving charges are

During a period of high power demand, the voltage output of the power company is reduced by 5.0%. By what percentage is the power in a resistor decreased?

In a given reversible process, the temperature of an ideal gas is kept constant as the gas is compressed to a smaller volume. Which one of the following statements about the gas is correct?

A laser is thrown upward with a speed of 12 m/s on the surface of planet X where the acceleration due to gravity is and there is no atmosphere. How long does it take for the laser to reach the maximum height?

A 1.1-kg uniform bar of metal is 0.40 m long and has a diameter of 2.0 cm. When someone bangs one end of this bar, a 1.5 MHz shock wave is travels along the length of the bar and reaches the Other end in 0.12 ms. What is the wavelength of the shock wave in the metal?

At room temperature, a typical person loses energy to the surroundings at the rate of 62 W. If this energy loss has to be made up by an equivalent food intake, how many kilocalories (food calories) Does this person need to consume every day just to make up this heat loss? (1 cal = 4.186 J)

A ball is thrown upward at a velocity of 19.6 m/s. What is its velocity after 3.0 s, assuming negligible air resistance?

As a rock sinks deeper and deeper into water of constant density, what happens to the buoyant force on it if it started above the surface of the water?

By how many decibels does the intensity level of a sound decrease when you triple your distance from a source of sound?

A train is traveling away from you at 120 km/h. It blows its whistle, and you hear a tone of 0.400 kHz. Take the speed of sound to be 340 m/s. What frequency does the whistle actually produce?

Which of the following quantities has units of a displacement? (There could be more than one correct choice.)

If the maximum voltage of an ac signal is 8.0 V, what is the rms value of this voltage?

You are driving along a highway at 35.0 m/s when you hear the siren of a police car approaching you from behind at constant speed and you perceive the frequency as 1340 Hz. You are relieved That he is in pursuit of a different driver when he continues past you, but now you perceive the Frequency as 1300 Hz. What is the speed of the police car? The speed of sound in air is 343 m/s.

The primary of an ideal transformer has 100 turns and its secondary has 200 turns. If the input voltage to the primary is 100 V, we can expect the output voltage of the secondary to be

A baseball is hit with a bat and, as a result, its direction is completely reversed and its speed is doubled. If the actual contact with the bat lasts 0.45 s, what is the ratio of the magnitude of the Average acceleration of the ball to its original speed?

A person running in place on an exercise machine for 10 min uses up 17 kcal (food calories). Another person exercises by repeatedly lifting two 2.5-kg weights a distance of 50 cm. How many Repetitions of this exercise are equivalent to 10 minutes of running in place? Assume that the Person uses negligible energy in letting down the weights after each lift. (1 cal = 4.186 J)