UMC review

a girl swings a ball in a perfect circle using a string. If she swings the ball twice as fast, what will happen to the force on the ball.

the force will increase

The _______________________ supplies the centripetal force requirement for the car to move in a horizontal circle. Without it, the car would turn its wheels but would not move in a circle

frictional force

What is the direction of the velocity at point B, if the ball is revolving clockwise?

down

A girl swings a toy plane in a perfect circle using a string. If the length of the string increases but the speed of the plane does not, what will happen to the force on the plane?

the force will decrease

You swing a bucket of water attached to a string in a circle above your head. What keeps the water in the bucket?

inertia

The lady has to apply a force on the bucket to keep it swinging in a circle. Which direction must that force go?

directed right, from our point of view

Bruno the bat flies at a speed of 0.5 m/s in circle of radius 1 m. What is his acceleration?

0.25 ms^-2

A stopper is attached to a string and spun in a perfect circle. If the mass of the stopper increases:

the centripetal force on the stopper will increase

At the bottom of a roller-coaster loop, gravity and the normal force point in opposite directions.

true

A 1, 450 kg racing car is moving at a constant speed of 115 m/s on a circular track. What will be the radius of the track if the force acting on the car to move in uniform circular motion is found to be 38, 125 N?

502.98 N

The centripetal force and centripetal acceleration vectors always point in the same direction.

true

The velocity is always _____ to the line of a circle.

tangent

Centripetal force and the speed of an object moving in a circle are _____________ related

directly (speed must be squared)

Where is the net force when the rollercoaster is at the top of the loop?

towards the center of the circle

Which one is the right relationship when you are at the bottom of a Ferris Wheel ride?

Fc= Fn-Fg

Calculate the mass of an object if it took 20 N to rotate it in a circle with a radius of 2 meters with a velocity of 4 m/s

2.5 kg

An object travels in a circle with a radius of 0.7m. If it takes the object 2s to go around the circle once, what is the speed of the object?

2.2 m/s

The force that is necessary to keep the bucket swinging in a circle is called the:

centripetal force

Calculate the velocity of an object moved around a circle with a radius of 1.65 m and an acceleration of 3.5 m/s².

2.4 m/s

A boy holds a toy pig by a string and whirls it in the air. Which object experiences the greatest tension force from the string?

they experience the same tension force

A 500 kg car travels in a circle with a speed of 20m/s. If the radius of the circle is 200m, what is the force on the car?

1000 N

A 900-kg car moving at 10 m/s takes a turn around a circle with a radius of 25.0 m. Determine the net force acting upon the car.

3600 N

Centripetal Force and the Radius of the circle are ___________________ related.

inversely

A particle P is moving in a circle with uniform speed. Which one of the following diagrams correctly shows the direction of the acceleration a and velocity v of the particle at one instant of time?

C

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.

1.66 N