unit 7 concept review
A proper conversion factor for degrees to radians would be
3pi=540
Marilyn (M) and her sister Sheila (S) are riding on a merry-go-round, as shown in Figure 7-1 (bird's-eye view).
They have different speeds, but the same angular velocity.
In uniform circular motion, there is a
constant angular velocity
The frequency unit of hertz is equivalent to
inverse seconds
When a rigid body rotates about a fixed axis all the points in the body have the same centripetal acceleration.
False
When a rigid body rotates about a fixed axis all the points in the body have the same linear displacement.
False
When a rigid body rotates about a fixed axis all the points in the body have the same tangential acceleration.
False
When a rigid body rotates about a fixed axis all the points in the body have the same tangential speed.
False
When a rigid body rotates about a fixed axis all the points in the body have the same angular acceleration.
True
When a rigid body rotates about a fixed axis all the points in the body have the same angular displacement.
True
When a rigid body rotates about a fixed axis all the points in the body have the same angular speed.
True
A car, driven around a circle with constant speed, must have
a centripetal acceleration.
The angular acceleration in circular motion
all the answers
James is twirling a rock around a horizontal circle on the end of a string. Figure 7-2 is a top view (motion is counterclockwise).
centripetal
If you whirl a tin can on the end of a string and the string suddenly breaks, the can will
fly off, tangent to its circular path
What is the direction of the force that acts on clothes in the spin cycle of a washing machine?
inward
A car travels in a circle with constant speed. The net force on the car
is directed toward the center of the curve
The radian unit is equivalent to a ratio of
length/length
Which of the following is NOT a unit of rotational speed?
meters per second
Does the centripetal force acting on an object do work on the object?
no, because the force and the displacement of the object are perpendicular
If the centripetal force on a particle in uniform circular motion is increased
the tangential speed will increase and/or the radius will decrease