Physics help??

Question

1) At an outdoor market, a 1.20-kg bunch of bananas are hung from a spring, stretching the spring by 1.50 cm. What is the force constant k of the spring?

2) Later on, after the bananas are sold, a small monkey jumps on the spring, setting it into oscillation with amplitude 20.0 cm and maximum speed 80.0 cm/s. What is the monkey’s mass?

Answer 1

Step 1:

(1)

Mass of the banana hung on the spring is 1.20 kg.

The displacement of the spring is 1.50 cm = 0.015 m.

Force exerted by the spring .

Force exerted by the spring and the gravitational force are in same direction.

So net force is equal to zero.

Force constant of the spring .

Solution:

Force constant of the spring .

Answer 2

Step 1:

(2)

Amplitude of the oscillation A = 20.0 cm = 0.2 m.

Maximum speed  V_max= 80.0 cm/sec = 0.8 m/sec.

Force constant of the spring .

Maximum speed of the mass on the spring is

Mass of the monkey is .

Solution:

Mass of the monkey is .