Quiz 9

1. The relation between the angle of rotation (θ) in radians and time (t) in seconds of a rotating body is given by the equation. θ = 2t3 + 3t2 + 10. a. Find displacement b. angular velocity and c. Angular acceleration after 4 seconds

3. A ceiling fan is spinning at 0.9 rev/sec when you turn down the switch. The fan's angular speed decreases at a rate of 0.2 rev/s² for 3 seconds. a. What is the angular speed at the end of the three seconds? b. How many revolutions does the fan undergo as the angular speed changes? Assume the angular acceleration is constant. c. During this slowing process there will be a particular time when the angular speed is 0.5 rev/s. What is the angular speed and angular acceleration in rad/s and rad/s² at this time? d. The arm of the fan is 0.6 m long. What is the speed of a point on the tip of the fan when the angular speed 0.5 rev/s? e. What is the centripetal acceleration of the tip of the fan at this time? f. What is the magnitude of the tangential acceleration of the tip of the fan at this time? g. What is the angle between the acceleration and velocity vectors of a point on the rim at this time?

The bigclaw snapping shrimp shown is aptly named—it has one big claw that snaps shut with remarkable speed. The part of the claw that moves rotates through a 90° angle in 1.3 ms. If we assume that the claw is 1.5 cm long and that it undergoes a constant angular acceleration:a. What is the angular acceleration in rad/s2?b. What is the final angular speed of the claw?c. What is the tangential acceleration of the tip of the claw?d. How fast is the tip of the claw moving at the end of its motion?

2. Write a detailed solution. Identify the given quantities and unknowns. Label them properly.

3. A merry go-round with a radius of 6.0 meters rotates at a speed of 8 revolutions per minute (rpm). a.Calculate for its angular speed in rad/s. b. Find the tangential velocity of merry go round. c. if the merry go round stops after one minute, what is the angular acceleration? d. Find the tangential

TRUE OR FALSE 1. Angular momentum is always positive. 2. An object that has a large angular velocity also has a lower angular         momentum.

1. A bicycle tire is rotating counterclockwise at 3.141 rad/s. Over the course of 10.0 seconds, the tire's rotation slows uniformly until it comes to a complete stop. wo = 3.141 rad/s Wo Fig. 4- a bicycle wheel spinning. a. What is the angular acceleration a during this time period? b. What is the angular displacement 40 after those 10.0 seconds? The angular velocity a piece of tape at the end of a meter stick I'm waving around increases from 0.00°/s to 90.0%/s in 2.00 seconds. c. What is the angle through which the piece of tape rotates? d. What is the tape's angular acceleration?

A child with mass 42 kg sits on the edge of a merry-go-round at a distance of 3.0 m from its axis of rotation. The merry-go-round accelerates from rest up to 0.40 rev/s in 10 s. a. What is the angular acceleration of the merry-go-round? Express this in radians/second. b. What is the angular velocity at 5 s? c. Calculate the centripetal acceleration and tangential acceleration at 5 s. d. What is the total acceleration at 5 s? e. If the coefficient of static friction between the child and the surface of the merry-go-round is 0.6, does the child fall off before 5 s? Hint: To determine this, calculate the frictional force and force due to the acceleration of the merry-go-round on the child. Compare the two forces to find which is larger than the other, therefore overcomes the other.

1.Mark bought a large pizza with a radius of 0.5m.He unmindfully pour pizza sauce along the pizza edge for a distance of 80.cm.Calculate the angular displacement of the pizza sauce.   2.What is the angular velocity of an object traveling in a circle of radius 0.75m with a linear speed of 3.5m/s?   3.What is the angular acceleration of a ball that starts at rest and increases its angular velocity uniformly to 5 rad/s in 10 s?

5. Jupiter orbits the Sun with speed 2079 m/s at an average distance of 71 398 000 m from the Sun. If Jupiter has a mass of 1.90×10^27 kg, what is its angular momentum as it orbits?    a. 4.30×10^39 kgm^2/s b. 1.89×10^35 kgm^2/s c. 3.67×10^35 kgm^2/s d. 2.82×10^38 kgm^2/s e. None of the above

A student is seated on a barstool with two heavy weights in her extended arms. She is rotating counterclockwise at a speed of w. She slowly bring her arms closer to her body. Based on this information which statement is true? A. The Angular Momentum increases. B. The Moment of Inertia, I, remains constant. C. The angular velocity, w increases. С. D. The Angular Momentum decreases. E. The Moment of Inertia, I, increases.

Which of the ff. best describes a scientific law?a.It implies something accurate b. It implies experimentation results c. It summarizes observed facts d.It describes and observes physical results  The rate of rotary motion is called a. Angular velocity b. Angular motion c. Angular displacement d. Angular acceleration What average force is necessary to stop a .45 caliber bullet of mass 15 grams and speed of 300 m/s as it penetrates a block to a distance of 5 cm?a.12.6 kN b.13.5 kN c.13.0 kN d. 12.0 kN

1.  Mark brought a large pizza with a radius of 0.5m.  He unmindfully pours pizza sauce along the pizza edge for a distance of 80 cm.  Calculate the angular displacement of the pizza sauce.  2.  What is the angular velocity of an object travelling in a circle of radius 0.75 m with a linear speed of 3.5 m/s?  3.  What is the angular acceleration of a ball that starts at rest and increases its angular velocity uniformly to 5rad/s in 10s

2. An object is in motion along a circular path with radius equal to 1.5 meters and the angular velocity is equal to 5 rad/s. a. What is the magnitude of velocity? b. What is the normal acceleration?