Ello mates uh can yall help me with 19 and 20 -

To practice problem-solving strategy 10.1 for energy conservation problems. a sled is being held at rest on a slope that makes an angle θ with the horizontal. after the sled is released, it slides a distance d1 down the slope and then covers the distance d2 along the horizontal terrain before stopping. find the coefficient of kinetic friction μk between the sled and the ground, assuming that it is constant throughout the trip.

In this lab you will use a cart and track to explore various aspects of motion. you will measure and record the time it takes the cart to travel certain distances, and then complete some calculations. in the space below, write a scientific question that you will answer by doing this experiment.

How did world cup soccer become cool?