A sound source plays middle C (262 Hz). How fast would the source have to go to raise the pitch to C sharp (271 Hz)? Use 343 m/s as the speed of sound.

An object is placed 20.0 cm in front of a concave mirror with a focal length of 9.0 cm. What is the magnification of the image?

A ray of light incident upon a mirror makes an angle of $36^{\circ}$ with the mirror. What is the angle between the incident ray and the reflected ray?

In a standing wave on a string fixed at both ends, how is the number of nodes related to the number of antinodes?

A man standing still at a train station watches two boys throwing a baseball in a moving train. Suppose the train is moving east with a constant speed of 20 m/s and one of the boys throws the ball with a speed of 5 m/s with respect to himself toward the other boy, who is 5 m west from him. What is the velocity of the ball as observed by the man on the station?

A toy rocket-launcher contains a spring with a spring constant of 35 N/m. How far must the spring be compressed to store 1.5 J of energy?

Write C if the italicized word is used correctly. Write I if the word is used incorrectly. The author took a dispassionate approach to the topic. He presented both sides of the issue evenhandedly and did not let his own feelings intrude.

You are in an auto traveling at 55 mph (24.6 m/s). A second auto is moving toward you at the same speed. Its horn is sounding at 475 Hz. What frequency do you hear? Use 343 m/s as the speed of sound.

A lead brick $5.0 \mathrm{cm} \times 10.0 \mathrm{cm} \times 20.0 \mathrm{cm}$, rests on the ground on its smallest face. Lead has a density of $11.8 \mathrm{g} / \mathrm{cm}^{3}$. What pressure does the brick exert on the ground?

A 0.180-kg ball falls 2.5 m. How much work does the force of gravity do on the ball?

An elevator lifts a total mass of 1.1 x 10³ kg a distance of 40.0 m in 12.5 s. How much power does the elevator generate?

A hiker shouts toward a vertical cliff 465 m away. The echo is heard 2.75 s later. What is the speed of sound of the hiker’s voice in air?

Five pulses are generated every 0.100 s in a tank of water. What is the speed of propagation of the wave if the wavelength of the surface wave is 1.20 cm?

Calculate the equivalent resistance of these parallel-connected resistors: $680 \Omega, 1.1 \mathrm{k} \Omega, \text { and } 10.2 \mathrm{k} \Omega$.