Mechanics | Relativity Answers

Awheel rotating about a fixed axis at 24 r.p.m. is uniformly accelerated for 70 seconds,
during which time it makes 50 revolution. Find (i) angular velocity at the end of this
interval, and (ii) time required for the speed to reach 150 r.p.m.
(Ans. - 61.4 r.p.m. ;3 min 55.6 s)

The car is moving forward with a force of 4000 N. Air is moving in a backward direction with a force of 1500 N and is acting on a car. what will be the direction of the moving car? *

A mass m1=1.8kg is attached to another mass m2=3.2kg with a light inextensible string passing over a frictionless pulley.m2 is surrounded by a viscous liquid .if the acceleration of m2 downward is 0.6m/s^2 . calculate the frictional force acting as a drag on m2

A particle moves from x= 6.62 m to x= 26.884 m and then to x=4.017 m. ∆ x =

You drop a rock into a well and count the seconds before you hear a splash. If you counted 10 seconds before you heard the splash, how deep is the well?

A particle performs a simple harmonic motion about a point x=0m, with amplitude 0.5m and frequency 4Hz. Given that it is momentarily at rest at x=0.5m with t=0s. Determine, the time required for the particle to move from point x=0 to a point 0.3m away.

The angular velocity of a disc of mass 3kg and radius 0.6m change from 10rev/s to 15rev/s in 0.07s. calculate the impulse on the disc.

The flywheel of motor has a mass of 300kg and a radius of gyration of 1.5m. the motor develops a constant torque of 2000Nm and the flywheel starts from rest.
(i) what is the angular acceleration of the flywheel?
(ii) what will be it's angular velocity after making four revolutions?
(iii) how much work is done by the motor during the first four revolutions?

A torque of 4Nm is applied to accelerate a wheel from rest to 6rev/sec in a time of 10sec. Determine
(i) angular acceleration
(ii) angular velocity
(iii) angular momentum
(iv) angular impulse
(v) power applied

The angular momentum of a flywheel having a Moment of inertia 0.125kgm^3 decreases from 3.0 to 2.0kgm^2/s^2 in a period of 1.5s
(i) Assuming a uniform angular acceleration, through how many revolutions will the flywheel have tuned?
(ii) how much work is done?