Classical Mechanics
# Torque

$m=13\text{ kg},$ as shown in figure above. The outer radius of the device is $R=7 \text{ m},$ and the radius of the hub is $r= 2 \text{ m}.$ When a constant horizontal force $F = 130 \text{ N}$ is applied to a rope wrapped around the outer rim of the device, the box hanging from a rope wrapped around the hub acquires an upward acceleration of magnitude $2 \text{ m/s}^2.$ Then what is the rotational inertia of the device about its axis of rotation?

A fixed pulley-like device is used to lift a box of massThe gravitational acceleration is $g= 10 \text{ m/s}^2.$

A cubic dice is sliding on a frictionless table. The dice is a cube with edges of length 1 cm and a mass of 30 g. A kid reaches down and gives a horizontal flick to the dice, causing it to change which face is up. What is the minimum impulse in **g~cm/s** the kid must give to the dice in order to change the face?

**Details and assumptions**

- The acceleration of gravity is $-9.8~m/s^2$.
- You can model the dice as a perfect cube of uniform density.
- The dice never leave the table