- #1
Priyadarshini
- 191
- 4
Homework Statement
A ball of mass 65 g is thrown vertically upwards from ground level with a speed of 16 m s–1. Air resistance is negligible. The ball takes time t to reach maximum height. For time t 2 after the ball has been thrown, calculate the ratio of the potential energy of ball to the kinetic energy of ball .
Homework Equations
T=(usinA)/g, where A=90
s= 1/2at^2 + ut
GPE=mgh
KE=1/2mv^2
The Attempt at a Solution
T=(usinA)/g
= 16/9.81
= 1.63s
so t/2= 0.816
at 0.816s,
s= (1/2 x 9.81 x 0.816^2) + (16 x 0.816)
= 16.322m
GPE=mgh
0.065 x 9.81 x 16.322
KE= 1/2mv^2
1/2 x 0.065 x v^2
v^2-u^2=2as
v^2=2 x 9.81 x 16.322
substituting,
KE= 1/2 x 0.065 x 2 x 9.81 x 16.322
= 0.065 x 9.81 x 16.322
So, GPE:KE
= (0.065 x 9.81 x 16.322) / (0.065 x 9.81 x 16.322)
=1:1
The answer is incorrect. The correct answer is 3:1.
Last edited: