PHY2053 Physics 1, Test 2 Exam With Answers Version B - 1 A...

____ 1. A vault is opened by applying a force of 300 N perpendicular to the plane of the door, 0.80 m from the
hinges. Find the torque due to this force about an axis through the hinges.
a.
120 N  m
b. 240 N
 m
c.
300 N  m
d. 360 N
 m
____ 2. A 3.0-m rod is pivoted about its left end. A force of 6.0 N is applied perpendicular to the rod at a distance of
1.2 m from the pivot causing a ccw torque, and a force of 5.2 N is applied at the end of the rod 3.0 m from the
pivot. The 5.2 N is at an angle of 30  to the rod and causes a cw torque. What is the net torque about the
pivot?
____ 3. A bucket filled with water has a mass of 23 kg and is attached to a rope, which in turn, is wound around a
0.050-m radius cylinder at the top of a well. What torque does the weight of water and bucket produce on the
cylinder if the cylinder is not permitted to rotate? ( g = 9.8 m/s
2
)