If a 7kg object is thrown straight upwards at a speed of 10m/s(meters per second)

To what height will it rise? note: gravitational constant = -9.8m/s

(In reply to Solution by Ravi Raja)

Yep, that's one way of getting it Ravi. As I'm sure you know you've used the first two equations of motion, alternatively you can use the third equation of motion directly:

v^2 = u^2 + 2as
Where v is the final velocity, u is the initial velocity, a is acceleration and s is distance.

Solving for v=0, u=10, a=-9.8 gives s = 5.102m

Clearly this assumes that gravity is the only factor considered regarding the deceleration of the object. When air friction is considered then you get Charlie's more complex answer. To further complicate Charlie's answer you could also introduce spin to the object......


One minor point of pedantry, the gravitational constant in the question should read -9.8m/s/s or -9.8m/(s^2) as it is an acceleration (-9.8m/s is a velocity).

Posted by fwaff on 2003-04-01 20:32:00