Which of the following Which of the following angles equals 2angles equals 2 radians? radians?

a.a. 36036000

b.b. 18018000

c.c. 0000

d.d. 3.143.1400

Ans: A

How would an angle in radians be How would an angle in radians be converted to an angle in degrees?converted to an angle in degrees?

a.a. The angle in radians would be multiplied The angle in radians would be multiplied by 180by 18000//

b.b. The angle in radians would be multiplied The angle in radians would be multiplied by 360by 36000//

c.c. The angle in radians would be multiplied The angle in radians would be multiplied by 180by 18000/2/2

d.d. The angle in radians would be multiplied The angle in radians would be multiplied by 2by 2

Ans: A

At the Equator the Earth has a radius At the Equator the Earth has a radius of 6380000 m and it rotates 360of 6380000 m and it rotates 36000 every 24 hours. What is the angular every 24 hours. What is the angular displacement of a person standing at displacement of a person standing at the equator for 3 hours?the equator for 3 hours?

a.a. 0.26 rad0.26 rad

b.b. 0.52 rad0.52 rad

c.c. 0.78 rad0.78 rad

d.d. 0.39 rad0.39 rad

Ans: C

A child sits on a carousel at a A child sits on a carousel at a distance of 3.5 m from the center distance of 3.5 m from the center and rotates through an arc length of and rotates through an arc length of 6.5 m. What is the angular 6.5 m. What is the angular displacement of the child?displacement of the child?

a.a. 1.9 rad1.9 rad

b.b. 0.93 rad0.93 rad

c.c. 3.0 rad3.0 rad

d.d. 5.0 rad5.0 rad

Ans: A

A ceiling fan initially at rest A ceiling fan initially at rest accelerates to a final angular speed accelerates to a final angular speed of 0.70 rad/s and rotates through of 0.70 rad/s and rotates through an angular displacement of 4.90 an angular displacement of 4.90 rad. What is the ceiling fan’s rad. What is the ceiling fan’s average angular acceleration?average angular acceleration?

a.a. 0.10 rad/s0.10 rad/s22

b.b. 0.05 rad/s0.05 rad/s22

c.c. 1.80 rad/s1.80 rad/s22

d.d. 0.60 rad/s0.60 rad/s22

Ans: B

The end of the cord on a weed The end of the cord on a weed cutter is 0.15 m in length. If the cutter is 0.15 m in length. If the motor rotates at the rate of 126 motor rotates at the rate of 126 rad/s, what is the tangential speed rad/s, what is the tangential speed of the cord?of the cord?

a.a. 628 m/s628 m/s

b.b. 25 m/s25 m/s

c.c. 19 m/s19 m/s

d.d. 63 m/s63 m/s

Ans: C

A stone on the edge of a tire with a A stone on the edge of a tire with a radius of 0.25 m has a centripetal radius of 0.25 m has a centripetal acceleration of 4.0 m/sacceleration of 4.0 m/s22. What is . What is the tire’s angular speed?the tire’s angular speed?

a.a. 1.0 rad/s1.0 rad/s

b.b. 2.0 rad/s2.0 rad/s

c.c. 3.2 rad/s3.2 rad/s

d.d. 4.0 rad/s4.0 rad/s

Ans: D

A 0.40 kg ball on a 0.50 m string A 0.40 kg ball on a 0.50 m string rotates in a circular path in a vertical rotates in a circular path in a vertical plane. If a constant angular speed of plane. If a constant angular speed of 8.0 rad/s is maintained, what is the 8.0 rad/s is maintained, what is the force that maintains circular motion force that maintains circular motion when the ball is at the top of the circle?when the ball is at the top of the circle?

a.a. 9.0 N9.0 N

b.b. 11 N11 N

c.c. 13 N13 N

d.d. 10.0 N10.0 N

Ans: C

The direction of an object’s The direction of an object’s centripetal acceleration while centripetal acceleration while moving in uniform circular motion moving in uniform circular motion isisa.a. Tangent to the circleTangent to the circle

b.b. Opposite to the direction of motionOpposite to the direction of motion

c.c. Toward the center of the circleToward the center of the circle

d.d. Outward from the center of the circleOutward from the center of the circle

Ans: C

The direction of an object’s linear The direction of an object’s linear speed while moving in uniform speed while moving in uniform circular motion iscircular motion is

a.a. Tangent to the circleTangent to the circle

b.b. Opposite to the direction of motionOpposite to the direction of motion

c.c. Toward the center of the circleToward the center of the circle

d.d. Outward from the center of the circleOutward from the center of the circle

Ans: A

The direction of the force The direction of the force maintaining an object’s circular maintaining an object’s circular path ispath is

a.a. Tangent to the circleTangent to the circle

b.b. Opposite to the direction of motionOpposite to the direction of motion

c.c. Toward the center of the circleToward the center of the circle

d.d. Outward from the center of the circleOutward from the center of the circle

Ans: C