As shown in the diagram, a 4800-kg cable car is descending a high hill. A counterweight of mass 4600 kg on the other side of the hill aids the brakes in controlling the cable car's speed.
The rolling friction of both the cable car and the counterweight are negligible. How much
braking force does the cable car need to descend at constant speed?

Two polarizers are oriented at 40∘ to each other and plane-polarized light is incident on them. if only 16 percent of the light gets through both of them, what was the initial polarization direction of the incident light?

Two cannon balls weighing 18 kg and 24 kg are chained together and fired horizontally with a velocity of 165 m/s from the top of a 21-m wall. the chain breaks during the flight of the cannonballs and the 18-kg cannonball strikes the ground at t = 1.5 s, at a distance of 240 m from the foot of the wall, and 7 m to the right of the line of fire. determine the position of the other cannonball at that instant. neglect the resistance of the air.

What are some important factors to consider when choosing a warm-up before your workout?