2. Uniform Circular Motion
Chapter 4:
Uniform Circular Motion
Chapter 4: Equilibrium

3. Projectile
- any body with initial velocity that follows a path called trajectory.

4. Example 1:
A 20 kg weight on a table is attached by a string to another 20 kg that is hanging over the edge of the table. Assuming that the coefficient of friction is 0.2, what is the acceleration and what is the tension in the string?

5. Example 2:
A 5.0 kg mass is accelerated from rest at the bottom of the 4.0 m long ramp by a falling 20.0kg mass suspended over a frictionless pulley. The ramp is inclined 30ᵒ ramp from the horizontal, and the coefficient of kinetic friction = 0.26.
(a) Determine the acceleration of the 5.0 kg mass along the ramp.
(b) Determine the tension in the rope during the acceleration on the 5.0 kg mass along the ramp

6. Example 3:
In the figure below, there is no friction on all contact surfaces. When the system is released from rest:
(a) What is the constant acceleration of the system?
(b) What is the tension in the cord connecting blocks A and B?
(c) What is the tension in the cord connecting blocks B and C?

7. Example 4:
Referring to the figure shown below, block A weighs 100 N, block B also weighs 100 N and block C weighs 500N. if the system is released from rest and there is no friction on contact surface of block B:
(a) What is the tension in the string connecting blocks A and B?
(b) What is the tension in the string connecting blocks B and C?
(c) What is the acceleration of block B?

8. Example 5:
A system of cords, knotted together at P and Q, supports the weights shown.
(a) What is the tension in cord A?
(b) What is the tension in cord B?
(c) What is the tension in cord C?
(d) What is the weight of block W?

9. Example 6:
The system shown below is equilibrium. If the hanging body A weighs 500 N:
(a) What is the tension in cord b?
(b) What is the tension in cord e?
(c) What is the weight of the hanging body B?

10. Example 7:
A monstrous spider holds a cute Easter bunny in its web using three threads. The bunny has a mass of 4 kg. Thread 1 is held on the left of the bunny, at an angle of 37ᵒ to the vertical. Thread 2 is held at angle of 30ᵒ above the horizontal on the right of the bunny. Thread 3 has a tension T3 = 7.50 N and is held at an angle 20ᵒ below the horizontal, also on the right.
(a) Draw the free-body-diagram of the bunny
(b) Find the tension in each thread

11. Example 8:
A 20kg block, m1, is sliding on a 10kg block, m2. The blocks are on a 20ᵒ slope and are connected by a light string looped over a pulley. All surfaces are frictionless. Find the acceleration of each block and the tension in the string that connects the blocks.

12. Example 9:
In the figure below, the pulleys are light and frictionless, and the coefficients of friction between the blocks and the surfaces are μk = 0.10 and μs = if the hanging block X moves down a distance of 0.5 m in 0.5 s starting from rest:
(a) What is the constant acceleration of the system?
(b) What is the tension in the cord connection the 40-kg block and the 10-kg block?
(c) What is the tension in the cord connection the 10-kg block and the 20-kg block?
(d) What is the mass of the hanging block X

13. Example 10: (a) What is the tension T3 in cord 3?
The system show is in equilibrium.
(a) What is the tension T3 in cord 3?
(b) What is the tension T4 in cord 4?
(c) What is the tension T5 in cord 5?
(d) What is the weight of block B?