2. An object is moving in a circular path at constant speed. If the radius of the circular path is doubled and the speed stays the same, then:   a) The acceleration decreases by four times.   b) The acceleration stays the same.   c) The acceleration is halved.   d) None of the above.   3. A 10 kg object is moving in uniform circular motion with a radius of 20 m. It takes the object 8 s to make one complete revolution.     A. Find the speed of the object.     B. Find the net force acting on the object.

A hiker gets lost in a forest. He walks half-way around a circle with a radius of 2.1 km in 2.0 hours. a) What distance did he walk? b) What was his average speed? c) What was his displacement? d) What was his average velocity?

2. The following table lists data for the speed and radius of three examples of uniform circular motion. Find the magnitude of the centripetalacceleration for each example.

3. A ball attached to a rope is spinning in a circle with a constant speed of 8m/s. If the length of the string is 0.4m, what is the acceleration a' (magnitude and direction) of the ball in the picture? 4. A ball is initially rolling 3m/s east along a table. It undergoes an acceleration of 0.4m/s² south for 2 seconds. What is the velocity of the ball after this acceleration? Write your answer as a tuple (vx, vy). 5. Consider these three vectors: A, B, and C. a. Draw these three vectors as a chain, and find their sum. b. Write the three vectors and their sum as tuples (vx, Vy). A = B = C= " → A + B + C = y A (0,2) X B C