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raise its center of gravity. lower its center of gravity. increase its mass. non

ID: 1440832 • Letter: R

Question

       raise its center of gravity.
       lower its center of gravity.
       increase its mass.
       none of the above

       tumble end over end in the air.
       spin about its axis in the air.
       move without any tumbling or spinning.
       There is no way to predict how the ball will fly through the air.

for a softball bat, where would you find the center of gravity?        In the thin handle
       Exactly halfway along the bat
       In the more massive end of the bat
       Somewhere outside of the bat itself when an object is in unstable equilibrium, it will move to

       raise its center of gravity.
       lower its center of gravity.
       increase its mass.
       none of the above

If a football is kicked directly through its center of gravity, it will ?

       tumble end over end in the air.
       spin about its axis in the air.
       move without any tumbling or spinning.
       There is no way to predict how the ball will fly through the air.

Doorknobs are placed at the edge of the door furthest from the hinges ?        to help add momentum to the door.
       because it just looks better there.
       to increase the force on the door.
       to increase the lever arm.

Explanation / Answer

Q1.

In the more massive end of the bat

Reason : center of mass will be located where most of mass is concentrated.

Q2.

when an object is in unstable equilibrium, it will move to

   lower its center of gravity.
Reason : The body will try to minimize it's potential energy, while reaching stable equilibrium position.

Q3.

If a football is kicked directly through its center of gravity, it will ?

move without any tumbling or spinning.
Reason : when force is applied through Center of gravity, no torque acts on ball. so no tumbling and spinning etc.

Q4.


to increase the lever arm.

Reason : The door must be moved (rotated) with least effort. For a fixed amount of torque, Force is smallest when lever arm is largest.

for a softball bat, where would you find the center of gravity?