Achild and sled with a combined mass of 50.2 kg slide down a frictionless hill that is 8.38 m high. if the sled starts from rest, what is its speed at the bottom of the hill?

here we can say that since the hill is friction less So total energy is now conserved

we can use the energy conservation principle now

here we can say that initial KE is zero as the child and sled is at rest

and the final potential energy will also be zero as the child will reach the bottom

So here we can say

so final speed will be 12.8 m/s

molecules are free to separate from each other and will take on the shape of the container. molecules move completely at random and high speeds. they vibrate in a fixed position and do not move around much. molecules expand to the edge of their container.