I believe the last one about the bike is correct.
Answer:
A) - 1.8 m/s
Explanation:
As we know that whole system is initially at rest and there is no external force on this system
So total momentum of the system must be conserved
so we will have

now plug in all data into above equation



so correct answer is
A) - 1.8 m/s
Answer:
Explanation:
- The expression for acceleration of the rolling body on an inclined plane is given as a = gsinФ/1 + k²/R²
- where Ф is the angle of inclination, R is the radius, k is the radius of gyration.
- The potential energy of the system is given as ; PE = mgh
- The potential energy will be constant for ring, cylinder, solid sphere, and hollow sphere.
- The total kinetic energy of the rolling body is ; KE = mv²/2 + Iw²/2
- Hence, the total kinetic energy of the ring, cylinder, solid sphere and hollow sphere will be constant.
2. The moment of inertia of the ring is given as ;
I = mR²
The moment of inertia of the ring is maximum and therefore reaches the bottom last.