A toy car slides down a slope. If the top of the slope is 2m higher than the foot of the slope, how fast will the car be moving when it reaches the foot? (Assume that all of its g.p.e is transformed to k.e?
Hi! In this question, we can use the change in gravitational potential energy to calculate the kinetic energy that the car will have at the foot of the slope, and therefore it's velocity at this point. The mass of the car does not need to be known, as the mass in the 2 energy equations will cancel. 1.Change in GPE = m x g x change in h = 9.81x2xm =(19.62m) J 2. KE = change in GPE, since the car started at rest. So 1/2mv^2=19.62m The m's both represent the mass of the car, so can be divied through by on both sides. Leaving us with 1/2v^2 = 19.62 3. By rearranging this equation, we get v^2 = 2 x 19.62 v^2 = 39.24 v = 6.26418.. v = 6.26m/s
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