Physics unit 6

An object that is moving at a constant speed of 4.0 m/s will move around a 20.0m circumference circle in ____ seconds

5.0 sec T 4.0m/s divided by 4.0 m/s = 20m divided by t4.0 = 5 seconds

Acceleration

An object moving in uniform circle motion has a constant speed but is changing direction; therefore, the object is accelerating.

An object can move with a constant velocity and have a changing speed?

False

True or false: a bug on a turning record player will make fewer turns per minute if it is located toward the center of the record

False

True or false: velocity of an object in uniform circular motion is directed towards the center of a circle

False

Any object moving in a circle or along a circular path had some physical _____ pushing or pulling the object towards the_____

Force, center

At all points along a circular path, and object's acceleration is directed _____

Inward

To say that there is a centripetal force requirement for an object moving in a circle means that

Inward force must be greater then any outside fore

An object that moves in a circle at a constant speed must be experiencing a net force becuase it

Is changing its direction

Inertia is related to an objects tendency to

Keep on moving with the same speed and direction

Non uniform circular motion

Moving in a circle with changing speed

Newtons law of inertia

Objects in motion stay in motion with the same speed and the same direction unless acted upon by an unbalanced force

Considering a merry- go- round, where person A sits 10 meters away from the center and person B sits 5 meters away from the center: Who has the greater linear speed?

Person A has a greater linear speed because the radius is greater than person B

Explain how an object moving in a circle with uniform circular motion can have constant speed, but not constant velocity.

Speed is magnitude only (scalar) and can stay the same. Velocity is a vector and has direction so the magnitude (speed component) can stay the same but the direction changes in circular motion

An unbalanced force can cause an object to ____

Speed up Slow down Change its direction

And object is moving in a circle at a constant speed. Which of the following best described the direction of the velocity vector?

Tangent to the circle

As an object moves in uniform circular motion, identity what direction each of the vectors face. A. Velocity

Tangent to the circle

What is uniform circular motion?

The motion of an object in a circle with a constant or uniform speed.

Considering a merry- go- round, where person A sits 10 meters away from the center and person B sits 5 meters away from the center: Who makes more turns per minute while the merry-go- round is in motion?

The period is the same. They are making the same number of revolutions in the same amount of time.

Objects that move in a circle are guaranteed to be accelerating because

Their direction of the velocity vector is changing

What is true of all accelerating objects?

They are changing their direction

Which phrase described the direction of the acceleration of an object that moves in a circle?

Towards the center

As an object moves in uniform circular motion, identity what direction each of the vectors face. B. Net force

Towards the center of the circle

As an object moves in uniform circular motion, identity what direction each of the vectors face. C. Acceleration

Towards the center of the circle

The word centripetal means

Towards the center of the circle

An inward force can not affect the speed of a tangentially moving object.

True

An object can move with constant speed and have a changing velocity?

True

An object that moves in a circle at a constant speed is accelerating

True

Centripetal force center school for objects moving in a circle, there must be an inward net force acting upon the object.

True

True of false: when you whirl a can on the end of a string, the centripetal force on the can is the pull of the string on the can.

True

True or false is the radius increases then the velocity increases

True

True or false: Centripetal acceleration and centripetal net force always points in the same direction

True

Average speed

total distance/total time