Question

A monkey of mass 20 kg rides on a 40 kg trolley moving with constant speed of 8 m/s along a horizontal track If the monkey jumps vertically to grab the overhanging branch of a tree, the speed of the trolley after the monkey has jumped off is ______.

विकल्प

• 8 m/s

• 1 m/s

• 4 m/s

• 12 m/s

Answer 1

A monkey of mass 20 kg rides on a 40 kg trolley moving with constant speed of 8 m/s along a horizontal track If the monkey jumps vertically to grab the overhanging branch of a tree, the speed of the trolley after the monkey has jumped off is 12 m/s.

Explanation:

Allow the trolley's final speed to become V.

When the monkey jumped off the trolley, the system's initial momentum in the x direction = (20 + 40) × 8.

Momentum along the x direction = (40) V.

Now, using momentum conservation along the x axis,

60 × 8 = 40V

V = 12 m/s

Hence, speed of the trolley will become 12 m/s.