how fast (in m/s) is the tool going just before it hits the ground?

Question

A worker at the top of a 551-m-tall television transmitting tower accidentally drops a heavy tool. If air resistance is negligible, how fast (in m/s) is the tool going just before it hits the ground?

Answer 1

We can find the speed of the heavy tool when it hits the ground from the law of conservation of energy (the potential energy of the heavy tool at the height of 551m above the ground becomes the kinetic energy at ground level):

Potential Energy =Kinetic Energy

PE=KE

mgh=1/2mv² the mass can cancel out

gh=1/2v² where g=9.81m/s²

v=√2gh

=√2*9.81m/s²*551m

= 104 m/s