221 – Lab 7 Rotational Motion and The Moment of Inertia E, = E, %3D K, +Ug0 +K„, = K, +Ugs +K,s 8,0 `r,0 8,f 1 m,V½,o +m„gY,0 +÷Io 1 m,v +m„gYh,s 2 + "h°h,0 ´h,f Note the position of the hanging mass is y,, and its velocity is v,. The moment of inertia is I for whatever is rotating. 1. Isolate the moment of inertia, algebraically from the above equation as all other variables have been measured.

Compute the combined moment of the two 85-lb forces about (a) point O and (b) point A. The moment is positive if counterclockwise, negative if clockwise. Assume a = 5.0 in., b = 2.2 in., F = 85 lb. Answers: (a) Mo= i (b) MA= Mi A F Ib-in. lb-in.

A single circular loop of wire of radius 0.25m is positioned in a uniform magnetic field of 0.25T  that points out of the page. What is the magnitude of the average EMF induced in the loop if it's orientation changes from being in the plane of the page to out of/into the page over a time period of 0.59seconds?

A figure skater performs a twisting jump. She rotates around her longitudinal axis 2 times in 0.65 s. What was her angular displacement in radians? A 4 В D 720 E 2m

Consider the rotational kinematic motion profile indicated below. t: 0 → 5 s = 0 deg/s , R O(0) = 0 deg = 0 deg/s Y(0) = 0 deg = 6 deg/s , Q Ф(0) = 0 deg O deg %3D t: 5 → 15 s P = 0 deg/s Ó = 6 deg/s Ý(t) = 3/cos(0(t)) deg/s Compute roll angle O at t = 15 s.

Compute the combined moment of the two 75-lb forces about (a) point O and (b) point A. The moment is positive if counterclockwise, negative if clockwise. Assume a = 8.2 in., b = 3.9 in., F = 75 lb. y | I F Answers: (a) Mo= (b) MA= i i b F lb-in. lb-in.

A force F of magnitude 58 N is applied to the gear. Determine the moment (positive if counterclockwise, negative if clockwise) of F about point O. Assumer 135 mm, 0-28% Answer: Mo N-m

A car wheel ball is initially at rest at the top of a ramp. If the energy of the car wheel is to be conserved. What must be the equation of conservation of energy if we take into account translational and rotational kinetic energies. Q Zoom A 2 mv2 = 2 mv? + ½ lw? B ½ mv2 = ½ mv,? + mgh, mgh, = 2 mv? + ½ lw² D ½ mv,? + mgh, = ½ mv,? + mgh, ½ mv? + mgh, = ½ mv,? + ½ lw?

A plane with a wingspan of d = 16 m loses control in flight and begins to spiral in a circle around the cockpit while in a vertical dive. It completes one rotation every t = 3.1 s.

1. X,Y and Z are points on a rigid body that rotates about center O as shown in the figure .Given that the angular velocity w is 2 rad/sec and the angular acceleration a is 3rad/sec?, calculate and check graphically the magnitudes and phase angles of the resultant acceleration of X,Y and z. OX = 5in ΟΥ- 1 in OZ = 5in %3D