Phy 112
Review
Hwk 1
1. A block hangs from two light strings. Find the angle T1 makes with the horizontal if T2 is 166N at
135° and the mass of the block is 20.4kg. The picture is not to scale. (ans 35°)
2. A ball rolls down an incline at 40° and off a table (y = 1.50m). The ball lands 0.813m from the
table edge. Find the height of the incline (h) if the ball has a mass of 1.50kg. (ans 0.154m)
3. A 5.00m uniform bar with a mass of 76.0kg is attached to a wall by a pin and held horizontal by a
string. The string makes a 30.0° angle with the bar and a mass of 15.0kg is suspended 4.00m
from the hinge. Solve for the tension in the string. (ans: 981N)
4. A 730N man stands in the middle of a frozen pond of radius 5.5m. He is unable to get to the
other side due to a lack of friction between his shoes and the ice. To overcome this difficulty a
friend throws him a 1.40kg physics book horizontally that he catches, at a speed of 5.0m/s. Find
how long does it takes him to reach the shore. (ans: 58.5sec)
1