Kinematics question

A book falls off a table that is 0.9m high. Taking g as 9.8ms^-2, find
(i) the speed at which the book is travelling when it lands on the floor
(ii) the time it takes to reach the floor

I don't need the answers, I just need the right equation to plug the numbers into. A brief explanantion would be helpful as well. Thanks :smile:

Reply 1

TenOfThem

18

(i) you know u, s, and a and you want v

Which equation involves these

(ii) you have u, s, a, and v and you want t

You can use any equation for this as you have so much

Reply 2

raheem94

13

Original post by pompompandapple

A book falls off a table that is 0.9m high. Taking g as 9.8ms^-2, find
(i) the speed at which the book is travelling when it lands on the floor
(ii) the time it takes to reach the floor

I don't need the answers, I just need the right equation to plug the numbers into. A brief explanantion would be helpful as well. Thanks :smile:

For part (a),

As the book falls off this indicates that the initial velocity is zero.
Acceleration is taken as 'g'.
Table is 0.9m high, hence the distance the book will fall is 0.9m

Use the equation,