In: Physics
A block of mass m begins at rest at the top of a ramp at elevation h with whatever PE is associated with that height. The block slides down the ramp over a distance d until it reaches the bottom of the ramp. How much of its original total energy (in J) survives as KE when it reaches the ground? (In other words, the acceleration is not zero like it was in lab and friction does not remove 100% of the original PE. How much of that original energy is left over after the friction does work to remove some?) m = 8.5 kg h = 5.5 m d = 5 m μ = 0.3 θ = 36.87°
PE =mgh
=(8.5)(9.8)(5.5)
=45815 J
Frictional force Fr= Nuk
=ukm g sin theta
= 0.3 (8.5 kg)(9.81 m/sec^2 )( sin 36.87)
=15.00 N
Work done by friction = frd
= 15(5.5)
=82.55 J
Remaining energy to be converted to KE = 45815 J- 82.55 J = 45723.45 J