Question
a body of mass 2kg is released from a point 100m above the ground.
Calculate its kinetic energy 80m from the point of release.?
Calculate its kinetic energy 80m from the point of release.?
Answers
oobleck
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.
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.
henry2,
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.