Question

central net force model worksheet 1:
radial net forces and circular motion

1. a bowling ball rolls down the hallway

a. to curve the ball turn in a smooth circular turn to the right, draw a picture to indicate how you would push on the ball to make it turn.
b. while you are curving the ball’s path, are the forces on the ball balanced? draw a force diagram for the ball.
c. is the ball accelerating? if so, what is changing about the velocity?

1. an airplane banks and makes a wide circle.

a. draw a force diagram for a head - on view of the banking plane.
b. name the force that allows the plane to travel in a circle.

Explanation:

1a Solution (Physics - Force and Circular Motion)

Step1: Recall Circular Motion Force

For circular motion, a centripetal force (toward the center) is needed. To curve right, push toward the left - center of the circular path.

Step2: Draw the Push

Draw the bowling ball, and an arrow from the ball toward the right - hand side's center of the circular turn (toward the left relative to the ball's forward motion to curve right).

Step1: Analyze Force Balance

In circular motion, there is a net centripetal force (not balanced). Balanced forces result in constant velocity (straight line or rest).

Step2: Draw Force Diagram

For the ball, forces are: weight (downward, \( \vec{F}_g = mg \) downward), normal force (upward, \( \vec{F}_N \) upward, balanced with weight), and the applied push force (toward the center of the circle, \( \vec{F}_{push} \) toward the center). So forces are not balanced (net force toward center).

Step1: Recall Acceleration Definition

Acceleration is a change in velocity (speed or direction). In circular motion, direction changes.

Step2: Determine Acceleration and Velocity Change

Yes, the ball is accelerating. The velocity's direction is changing (even if speed is constant, changing direction means acceleration, centripetal acceleration \( a_c=\frac{v^2}{r} \) toward the center).

Answer:

(Diagram description) Push the ball with a force vector directed toward the center of the intended right - curved circular path (e.g., if the ball is moving forward, the push is to the left - side of the ball's path to make it curve right).

1b Solution (Physics - Force Balance in Circular Motion)