Question

a driver of car travelling at 52km/h applies the break and accelerates uninfomly in the opposite direction. the car stops in5s. another driver going at3km/h in another car applies his brakes slowly and the stops in 10s. on the same graph paper plot the speed versus time graphs for the two cars. which of the two cars travelled farther after the brakes were applied?

Answer 1

The data given in this numerical problem are in different units. So, we should first convert kmunit into munit. For first car: Initial velocityFinal velocity,Time taken,For second car : Initial velocity,Final velocity,Time taken,The distance travelled by a moving body is given by the area under its speed-time graph. So, Distance travelled by the first car = Area of the triangle Similarly,Distance travelled by the second car = Area of triangle COD Thus, the second car travels 4.1m and the first car travels36 m before coming to rest. So, the second car travelled farther after the brakes were applied.