A 30.0 kg door is 1.00 m wide, as shown in the diagram. A force of 85.0 N is applied is applied 0.750 m from the hinges at a 60° angle from the door. What is the angular acceleration with which the door swings open? (Hint: The moment of inertia of the door can be calculated as a rod of uniform mass rotating from the end:  .) a. 5.52 rad/s2 b.1.84 rad/s2 c.6.38 rad/s2 d.2.60 rad/s2

A bar on a hinge starts from rest and rotates with an angular acceleration a = 15 + 7t, where a is in rad/s? and t is in seconds. Determine the angle in radians through which the bar turns in the first 3.93 s. rad

An optical disk drive in your computer is spinning at 10,000 rpm (1045 rad/s).  It decelerates to a rest in 0.42 s.   a. Find the rotational inertia of the disk given that its mass is 17 grams. b. Find the magnitude of the torque required to decelerate the disk.

20. The 57.2cm diameter disk rotates counterclockwise on an axle through its center. F1=42.6N, F2=70.8N, F3=70.8N, F4=42.6N, and d=5.34cm. What is the net torque about the axle? Let the counterclockwise direction be positive. F31 +F₂ F d 45⁰

A 0.24 m radius grinding wheel takes 5.8 s to speed up from 2.6 rad/s to 5.9 rad/s. What is the wheel’s average angular acceleration?

The wheel and axle have forces applies tangentially as shown in the figure. There is also a frictional torque of 0.02 Nxm on the wheel, once the wheel starts moving. The radius of the axel is 20 cm and the radius of the wheelis 60 cm and F1 = 2.4 N, F2 = 3.0 N and F3 = 1.2 N. a. Calculate the net torque on the moving wheel due to the applied forces F1 F2 and F3. b. What direction of rotation would the applied forces cause? Explain. c. What is the direction of frictional torque? Explain. d. Calculate the net torque on the wheel and axle.

A wheel with thin spokes can be considered a hoop, where I=mr. A bicycle wheel has a mass of .35 kg with a radius of .30 m and is spinning at 25 rad/s in the positive direction. Brakes apply a force of friction of 15 N at the rim. We will consider the rim of the wheel to be on the very outside of the wheel. (Remember significant digits.) a.) What is the direction of the torque provided by the brakes (positive or negative) b.) What is the magnitude of the torque applied by the brakes? Nm c.) What is the moment of angular inertia of the wheel? kgm2 d.) What is the angular acceleration of the wheel? rad/s? e.) How far does the wheel travel (in radians) before coming to rest? rad f.) How long does this take? s g.) With faulty brakes, only 8 N can be applied. How long would it take to stop the wheel under these conditions? s MacBook Pro

A 0.37 m radius grinding wheel takes 6.1 s to speed up from 2.9 rad/s to 6.8 rad/s. What is the wheel's average angular acceleration?

The figure below is for a 50 kg-m2 object. o(radis) 60.0 40.0 20.0 -20.0 2.0 4.0 t(s) Find the net torque. Find the angular displacement at t = 2.25 s.

A circular disk with a radius of 0.37 m is subject to 2 tangentially applied forces. The disc is fixed such that it will rotate about its center. Both forces produce a torque in the same direction. F1 = 4.7 N applied at the outer edge of the disc. F2 = 3.2 N applied at a distance of 0.3 from the center of the disc. What is the net torque on the disc?