UARK Physics 1 exam 2 MC

A child swings a ball on the end of a string in a vertical circle. When the ball is moving upward, and the string is horizontal the string breaks. What happens to the ball?

It goes straight up in the air

A car is traveling at a constant 32 m/s on a level road. What is the linear speed at the top and bottom of a tire?

Top- 64, bottom-0

Three forces of equal magnitude are applied to a door separately. Force A is perpendicular to the door half-way between the hinges and the doorknob. Force B is perpendicular to the door at the doorknob. Force C is at a 45° angle to the door at the doorknob. Which force produces the largest torque about the hinges?

Forces A and B produce the same torque which is larger than C

You want to slide your couch to the other side of the room. Which is harder, getting it moving, or keeping it moving? Why?

Getting it started because static>kinetic

The normal force on a stationary child with mass M on a slide at an angle theta above the horizontal is

Mg Cos Theta

You are pulling a chair up a ramp into a moving van. The chair is moving at a constant speed. What direction is the net force on the chair?

Net force is 0

You throw 2 balls with the same amount of force. The red ball has 3 times the mass of the green ball. How do the accelerations of the two balls compare?

The green ball has 3 times the acceleration of the red ball

You drop a shoe on the floor. Which one experiences the larger force during the collision?

They experience the same force.

You are sliding a stack of chairs across a stage to setup for a presentation. If the force you apply is 15 degrees below the horizontal, how does the normal force compare to the weight of the chairs?

Normal is larger than the weight

A rock in deep space, far from other objects, moves in a straight line at a steady 43 m/s. What can be said about the forces acting on the rock?

No forces are acting on the rock, net force is 0

Two small balls with the same mass attract each other gravitationally with a force of F. If the mass between the balls is tripled, but the distance remain the same, what is the magnitude of the gravitational force on each one?

F/9

Two small balls with the same mass attract each other gravitationally with a force of F. If the distance between the balls is decreased to 1/3, but the masses remain the same, what is the magnitude of the gravitational force on each one?

9F

A disk is spinning about its center at a constant rate. A red dot is at the edge of the disk and a green dot is halfway between the edge and center. What can be said about the motion of the dots?

the dots have the same angular velocity, but the red dot has a larger tangential velocity

Phobos is a small moon orbiting Mars. Which one experiences a larger gravitational force?

Mars because Phobos has a smaller mass.

In order for a ball to move at a constant speed along a circular path, the acceleration it experiences must

Point directly at the center of the circle