All AP Physics 1 Resources
Example Questions
Example Question #51 : Circular And Rotational Motion
When a road is dry, a particular car can safely navigate a turn with a radius of curvature at without slipping. What is the coefficient of friction if this is the fastest speed the car can take this turn? Is this the static or kinetic coefficient?
, kinetic
, kinetic
, kinetic
, static
, static
, static
For the car going around a flat turn, the force of friction is the only force keeping the car in a circular path. This lets us equate the centripetal force to the force of friction.
Substitute and solve for the coefficient of friction.
Since the tires are rotating but not slipping on the surface, this is the coefficient of static friction, .
Example Question #21 : Centripetal Force And Acceleration
On a wet road, the coefficient of static friction between a car's tires and the flat road is . What is the maximum speed a car can safely navigate a turn with a radius of curvature?
When a car is going around a flat turn, the only force keeping the car going along a circular path is the force of friction, which is equal to the centripetal force. We do not need the mass of the car to calculate the maximum speed, as we will show below.
Rearrange these equations and solve for the velocity.
Example Question #22 : Centripetal Force And Acceleration
If a car can safely go around an icy banked turn at a speed of , what is the radius of curvature of the turn?
Cannot be determined without knowing the mass of the car
For a car going around a banked turn with no friction, a component of the normal force is what provides the centripetal force. The radius of the curve can be calculated without knowing the mass of the car.
Example Question #54 : Circular And Rotational Motion
You tie a rock to a rope and swing it above your head with a frequency of . The distance from your hand to the rope is . Determine the centripital force experience by the rock.
None of these
Centripital acceleration is
Force is defined as
Using subsitution
The rock has a frequency of .
Each circle it makes has a circumference of , which is equivalent to .
That means it travel in , which is
Plugging in our values:
Example Question #23 : Centripetal Force And Acceleration
A ball attached to a 1 meter-long string is being spun around and is traveling at .
What is the centripetal acceleration of the ball?
We use the formula for centripetal acceleration:
Where is the centripetal acceleration, is the velocity and is the radius (1m).
Plug in these known values and solve.
Example Question #102 : Circular, Rotational, And Harmonic Motion
A person of mass is riding a ferris wheel of radius . The wheel is spinning at a constant angular velocity of . Determine the force exerted on the rider by their seat at the top of the ferris wheel.
None of these
Convert to :
Definition of centripetal acceleration:
Plug in values:
Superposition of forces:
Where both and are pointing down, and thus negative.
Solve for
Plug in values:
Example Question #103 : Circular, Rotational, And Harmonic Motion
A person of mass is riding a ferris wheel of radius . The wheel is spinning at a constant angular velocity of . Determine the force exerted on the rider by their seat at the bottom of the ferris wheel.
Convert to :
Definition of centripetal acceleration:
Plug in values:
Superposition of forces:
Where is pointing down, and thus negative. However, is pointing up, and thus positive.
Solve for
Plug in values:
Example Question #24 : Centripetal Force And Acceleration
Radius of earth:
Estimate a centripetal acceleration of someone standing on the equator with respect to the center of the earth.
None of these
A person on the equator travels in a circle with the same radius as the earth's every .
Thus, distance divided by time:
Convert to and plug in values:
Use the definition of centripetal acceleration:
Plug in values:
Example Question #21 : Centripetal Force And Acceleration
Earth mass:
Earth distance from the Sun:
Velocity of the Earth:
Estimate the centripetal acceleration of the earth in relation to the sun.
The velocity of the earth is
Convert to
Plug in values:
Example Question #21 : Centripetal Force And Acceleration
Estimate the centripetal acceleration of a car driving around a long perfectly circular track.
Convert to
Convert to :
Use the equation for centripetal acceleration: