A bobsled has a momentum of 4000 kg•m/s to the south. Friction on the
track reduces its momentum to 2500 kg•m/s to the south. What impulse is
applied to the bobsled by the friction?
A. 1500 kg-m/s north
B. 1500 kg-m/s south
C. 6500 kg•m/s south
D. 6500 kg•m/s north

Which type of wave can travel without a medium

Students design a model roller-coaster track. they place a rubber ball at the highest point on the track and let it go. the ball rolls along the track pulled only by the force of gravity. eventually, it comes to a stop. which change to the design will result in the ball moving the greatest distance?

Acaterpillar tries to climb straight up a wall a meter high, but for every 2 cm up it climbs, it slides down 1 cm. eventually, it reaches the top. when it reaches the top, it does not pull itself over so it will slide down 1 cm. what is the total displacement traveled?