how long does it take to fall 80m? 4.9t^2 = 80
using that t, get v = 9.8t
using that v, get KE = 1/2 mv^2
If you massage things a bit, you can do it in one formula, but it's often best just to stick to the basic equations of motion.
a body of mass 2kg is released from a point 100m above the ground.
Calculate its kinetic energy 80m from the point of release.?
2 answers
V^2 = Vo^2 + 2g*(100-80) = 0 + 19.6*20 = 392,
V = 19.8 m/s @ 80 m above gnd.
KE = 0.5*M*V^2 = 0.5*2*392 = Joules.
V = 19.8 m/s @ 80 m above gnd.
KE = 0.5*M*V^2 = 0.5*2*392 = Joules.
5 answers