Question

Erica (35 kg ) and Danny (44 kg ) are bouncing on a trampoline. Just as Erica reaches the high point of her bounce, Danny is moving upward past her at 4.9 m/s . At that instant he grabs hold of her.

Answer 1

v= 2.66 m/sec

Explanation:

supposing we have to find their speed just as he grabs her.

Applying law of conservation of Energy

That is

p_i= p_f

Initial momentum = p_i = 35×0+ 44×4.9= 210.6 kg.m/sec.

final momentum p_f= (35+44)v

let the final velocity of combined body be v

therefore,

79v= 210.6

v= 2.66 m/sec.