Centripetal Force

A car is rounding a bend as shown in the diagram. Which arrow correctly shows the direction of the car's velocity?

• A

• B

• C

• D

Answer explanation

Tangential velocity

Which Vector represents the acceleration of the ball?

• A

• B

• C

• D

Answer explanation

Because if you decompose the vectors into their X and Y components and add them together the resultant vector points to the center.

CIRCULAR MOTION CONCEPTS: An object moves in a perfect circle on the end of a string.  If the string breaks, which letter represents the direction in the object would move in at that instant?

• A

• B

• C

• D

Answer explanation

If there is no centripetal force than the ball will go in a straight line because of inertia, Newton's 1st Law of motion.

A horse gallops around a circular arena.  The centripetal force on the horse is ___.

• directed outward

• tension

• directed toward the center of the arena

• 9.8 N

Answer explanation

The force is always to the center when you go in a circle

Calculate the amount of centripetal force it takes for a softball pitcher to rotate a ball with a velocity of 3 m/s if the ball weighs .12 kg and her arm is .65 meters long.

• .38

• 1.23

• .55

• 1.66 N

Answer explanation

What provides the centripetal force for a car moving on a level, horizontal circular track?

• static friction

• kinetic friction

• The Normal Force

• Tension

Why should you reduce speed around a turn if the road is icy?

• Because your car will travel in a straight line unless forced to do otherwise

• Because the ice reduces the frictional force between the tires and the road.

• Because a minimum amount of centripetal force is required to keep your car moving around the curve.

• All of the above.

Answer explanation

Friction provides the centripetal force to go in a circle in this case

Calculate the centripetal force required to make a 5 kg ball move 4 m/s in a circle with a radius of 2 m.

• 10 N
• 20 N
• 30 N
• 40  N

What's the centripetal acceleration of an object traveling 2.3 m/s around a circle of diameter 0.6 m?

• 5 m/s²

• 17.63 m/s²

• 10 m/s²

• 8.81 m/s²

When an object is in circular motion it is constantly changing its velocity.

• True
• False