A ball is dropped from a height of 45m above the ground. ...
A ball is dropped from a height of 45m above the ground. Calculate the velocity of the ball just before it strikes the ground. (Neglect air resistance and take g as 10ms−2 )
21.2ms−1
30ms−1
300ms−1
450ms−1
900ms−1
Correct answer is B
v2=u2+2as=02+2×10×45⇒v2=900m2s−2⇒v=√900m2s−2⇒v=30ms−1