Q. A hiker determines the length of a lake by listening for the echo of her shout reflected by a cliff at the far end of the lake. She hears the echo 1.44 s after shouting. Determine the length of the lake. Assume the speed of sound to be 340 m/s.
Q. A 3.0-m-long rigid beam with a mass 140 kg is supported at each end. An 75 student stands 2.0 m from support 1.
How much upward force does support 1 exert on the beam?
How much upward force does support 2 exert on the beam?