Question

27. A stone is thrown vertically upwards by a boy. It
returns to his hands in 3 seconds. How high does
the stone rise?
fa) 11 m (6) 12 m (C) 3 m (d) 44 m​

Answer 1

Explanation:

Tf=3s

ø=90°

T=2usin90/g

3=2usin90/10

30=2usin90

u=15

H=u²sin²90/2g

H=15²/2×10

H=225/20=11.25~11m

when g=9.8m/s²

T=2usinø/g

3×9.8=2×u×1

u=14.7m/s

H=u²sin²ø/2g

H=14.7²/2×9.8=7m