a 65 kg sled starting from the rest slides down a 14 m high frictionless ramp. at the bottom of the ramp the sled encounters a level area that is not frictionless. how much work is done by friction to stop the sled?
To determine the work done by friction to stop the sled, we need to calculate the change in kinetic energy of the sled between the top and bottom of the ramp.
First, we can find the potential energy of the sled at the top of the ramp using the formula: Potential Energy = mass (m) × acceleration due to gravity (g) × height (h).
Potential Energy = 65 kg × 9.8 m/s^2 × 14 m = 12796 J (joules)
At the bottom of the ramp, the potential energy is converted into kinetic energy, so the initial kinetic energy (K1) of the sled is equal to the potential energy.
K1 = 12796 J
The final kinetic energy (K2) at the bottom of the ramp is zero because the sled comes to a stop.
The work done by friction (W) can be calculated using the equation: Work = K2 - K1.
W = 0 J - 12796 J = -12796 J
The negative sign indicates that the work done by friction is in the opposite direction of motion (opposing the motion of the sled).
Therefore, the work done by friction to stop the sled is -12796 joules.