Which type of wave needs a medium to travel? ANSWER: sound waves, because they travel by oscillating molecules
What do both sound and light waves transfer?
ANSWER: Energy
How does an increase in amplitude affect sound and light waves?
ANSWER: louder sound and brighter light
What happens to the wavelength and speed of the waves when the frequency increases?
ANSWER: The wavelength decreases, but speed remains the same.
Which statement about sound waves is correct?
ANSWER: The animated particles are more concentrated along wave crests and less dense along wave troughs.

As you are trying to move a heavy box of mass m, you realize that it is too heavy for you to lift by yourself. there is no one around to , so you attach an ideal pulley to the box and a massless rope to the ceiling, which you wrap around the pulley. you pull up on the rope to lift the box. use g for the magnitude of the acceleration due to gravity and neglect friction forces. once you have pulled hard enough to start the box moving upward, what is the magnitude f of the upward force you must apply to the rope to start raising the box with constant velocity? express the magnitude of the force in terms of m, the mass of the box.

Agroup of monkeys is trying to cross the river in a rowboat. the maximum buoyant force on the rowboat is 2,000 n. the weight of the rowboat is 1,000 n. each monkey has a weight of 150 n. how many monkeys can safely cross in the rowboat at one time? explain your reasoning, including any calculations you used to find the answer.

Aforce of 8,480 n is applied to a cart to accelerate it at a rate of 26.5 m/s2. what is the mass of the cart?