In which situation is Torque positive or negative?

A dentist's drill starts from rest. After 3.10 s of constant angular acceleration it turns at a rate of 2.70 ✕ 104 rev/min. (a) Find the drill's angular acceleration. (b) Determine the angle (in radians) through which the drill rotates during this period.

Starting from rest, a disk rotates about its central axis with constant angular acceleration. In 8.00 s, it rotates 12.5 rad. During that time, what are the magnitudes of (a) the angular acceleration and (b) the average angular velocity? (c) What is the instantaneous angular velocity of the disk at the end of the 8.00 s? (d) With the angular acceleration unchanged, through what additional angle (rad) will the disk turn during the next 8.00 s? (a) Number i (b) Number (c) Number (d) Number i Units Units Units Units ION

In a stunt that his friends say is crazy, a physics student jumps off a high diving platform and makes 1.5 complete revolutions on the way from the 12-m high platform to the swimming pool. The student jumps off the platform horizontally so he has no initial vertical velocity. What is the average angular velocity during the dive?

True or False: Net torque always equals moment of inertia times angular acceleration.

Force F = (- 7.7 N )i + (4.6 N )j acts on a particle with position vector 7 = (2.5 m )i + (4.2 m )j. What are (a) the %3D magnitude of the torque on the particle about the origin and (b) the angle between the directions of 7 and F ? (a) Number i Units (b) Number i Units

A uniform solid disk of radius 3 m and mass 2.0 kg rolls without slipping. to the bottom of an inclined plane. If the angular velocity of the disk is 8 rd/s at the bottom, what is the height of the inclined plane? 22m 19.71m None of the above 6.73m 44.1 m/s

Starting from rest, a disk rotates about its central axis with constant angular acceleration. In 9.00 s, it rotates 21.0 rad. During that time, what are the magnitudes of (a) the angular acceleration and (b) the average angular velocity? (c) What is the instantaneous angular velocity of the disk at the end of the 9.00 s? (d) With the angular acceleration unchanged, through what additional angle (rad) will the disk turn during the next 9.00 s? (a) Number i (b) Number i (c) Number (d) Number i Units Units Units Units <

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.

Force F = (- 5.5 N )î + (2.9 N )ĵ acts on a particle with position vector 7 magnitude of the torque on the particle about the origin and (b) the angle between the directions of 7 and F ? = (4.3 m )î + (8.3 m )§.What are (a) the