I will not rate if you don\'t show your work. I am trying to learn how to do the
ID: 2244276 • Letter: I
Question
I will not rate if you don't show your work. I am trying to learn how to do these problems myself. Thanks!
1. A 40.0 kg gate is hung on a fence post as shown. Draw the free body diagram of the gate. You may assume that each hinge supports half the weight and the center of
mass of the gate is in the center of the gate (at the black dot halfway between the hinges).
a. Draw a free body diagram
b. Write down the equations for equilibrium clearly identifying your pivot point.
c. What is the force exerted by the top hinge on the gate? (F top x and F top y)
d. What is the force exerted by the bottom hinge on the gate? (F bottom x and F bottom y)
2.The figures below show sets of possible momentum vectors before and after a collision (no external forces are acting). Which set(s) could actually occur?
Explanation / Answer
F top y = F bot y = 40 / 2 * 9.8 = 196 N since each hinge supports 1/2 of the weight
If we take torques about the bottom hinge
(F top x) * (1.2 / 2) = 40 * 9.8 * (3.66 / 2) Counterclockwise torque
(F top x) = 20 * 9.8 * 3.66 / .6 = 717 N
(F bot x) = -(F top x) for horizontal equilibrium
2. All but the third case could occur because "before" has net momentum in the
downward direction while "after" has net momentum in the upward direction
violating conservation of momentum.
The first case could occur when a light object collides elastically with a heavier object.
The second case could when a heavy collides elastically with a lighter object.
The fourth case could occur when both objects stick together.