Given below are two statements: Statement I: A truck and a car moving with the same kinetic energy are brought to rest by equal retarding forces. Both stop in equal distances. Statement II: A car moving east takes a turn and then moves north with unchanged speed. Its acceleration is zero. Choose the correct answer.
Options

Question

Given below are two statements: Statement I: A truck and a car moving with the same kinetic energy are brought to rest by equal retarding forces. Both stop in equal distances. Statement II: A car moving east takes a turn and then moves north with unchanged speed. Its acceleration is zero. Choose the correct answer.

Options

G1 Physics · Accepted Answer

For stopping under a constant retarding force, work done = change in kinetic energy. If both vehicles have the same initial kinetic energy and the same retarding force, then Fs = K so the stopping distance s is the same. Statement I is true. In Statement II, speed is unchanged but velocity direction changes from east to north, so velocity changes and acceleration is not zero. Thus Statement II is false. Hence option A follows.