A horizontal platform in the shape of a circular disk rotates freely in a horizontal plane about a frictionless vertical axle. The platform has a mass M = 100 kg and a radius R = 2.0 m. A student whose mass is m = 60 kg walks slowly from the rim of the disk toward its centre. If the angular speed of the system is 2.0 rad/s when the student is at the rim, (a) what is the angular speed when he reaches a point r = 0.50 m from the centre? (b) What is the kinetic energy of the system before and after the student walks inward?
University of Ilorin PHY101 2026-exam past question
- (a) 4.09 rad/s; (b) 880 J before, 1801 J after
- (a) 2.00 rad/s; (b) 880 J before and 880 J after
- (a) 8.18 rad/s; (b) 880 J before, 3602 J after
- (a) 4.09 rad/s; (b) 1801 J before, 880 J after
Register free to see the answer and step-by-step explanation
More University of Ilorin PHY101 2026-exam past questions
Related questions
- A car's suspension consists of springs with an overall effective spring constant of 120 kN/m. How much would you have to compress the sprin…
- An object rotates with angular momentum L. What will happen to its angular velocity if its moment of inertia is doubled?
- A 3.00 kg particle has a velocity of (3.0i - 4.0j) m/s. Find the magnitude of its total momentum.
- An object A is moving with 5 m/s and object B is moving with 20 m/s in the same direction (positive x-axis). Find the velocity of B with re…
- A man climbs a mountain with an amount of energy E. The energy he gains when descending the mountain is equal to:
- When a box is dragged on the floor, the work done on the box in the form of potential energy is:
