Question

State two factors on which the position of Center of Gravity of a body depends.

Case 1: Lata cuts a potato into two halves, using a cutter which belongs to a Class II lever. She needed effort E1. Case 2: Then she cuts one half of this potato again, but this time she needed effort E2. If E1 > E2 then:

The graph shows load against effort for a lever with load and effort on the same side of the fulcrum.

A man fires a gun and hears its echo after 3 s. The man then moves 80 m towards the hill and fires his gun again. This time he hears the echo after 2.5 s. Calculate the speed of the sound. State one reason of using ultrasonic waves in SONAR.

The diagram below displays four solid plastic balls attached to wires, all mounted on a wooden base. When a person shakes the wooden base back and forth at a steady pace, the balls begin to vibrate as well. It is noted that while all the balls vibrate, only one of them vibrates vigorously.