Question

The velocity-time graph of a ball of mass 200 g moving along a straight line on a long table is given in Fig. How much force does the table exert on the ball to bring it to rest?

Answer 1

Explanation:

Displacement(s)=area under the curve of v-t graph= 1/2×10×20 cm= 100 cm

initial velocity(u)=20 cm/s (from graph)

final velocity(v)=0 cm/s (from question)

acceleration (a)= ?

we know,

v²=u²+2as

=> v²=u²-2as [ Because a is retardation here]

=>a=(u²-v²)/2s

=>a= (20²−0² )/(2×100)=400/200=2 cm/s^2

=> Force required=mass × acceleration

= (200× 2) Dyne = 400 Dyne