Homework Solution

TP 3-2

Given:

    m = 0.5 kg

    h = 5 m

Find:

    velocity just before hits ground if dropped (from rest and ignoring air resistance)

Science:

    KE_i + PE_i = KE_f + PE_f

    PE = mgh

    KE = (1/2)mv²

Solve:

    KE_i + PE_i = KE_f + PE_f

    0 + mgh = (1/2)mv² + 0        with h measured from the ground

    v = (2gh)^1/2 = [(2)(9.80 m/s² )(5 m)]^1/2  = 9.9 m/s