Author Question: The figure shows a 2000 kg cable car descending a high hill. A counterweight of mass 1800 kg on the ... (Read 91 times)

jhjkgdfhk · **on:** Jul 29, 2018

The figure shows a 2000 kg cable car descending a high hill. A counterweight of mass 1800 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?

A) 3800 N
B) 2900 N
C) 2000 N
D) 980 N

Question 2

A 4.00-kg box sits atop a 10.0-kg box on a horizontal table.

The coefficient of kinetic friction between the two boxes and between the lower box and the table is 0.600, while the coefficient of static friction between these same surfaces is 0.800. A horizontal pull to the right is exerted on the lower box, as shown in the figure, and the boxes move together. What is the friction force on the UPPER box?

A) 19.3 N to the right
B) 19.3 N to the left
C) 23.5 N to the right
D) 31.4 N to the right
E) 31.4 N to the left