Answer:
a- hollow sphere
The hollow sphere will reach the bottom of the ramp first because it has the lowest rotational inertia of the four objects and will experience the greatest angular acceleration from the applied torque.
Step-by-step explanation:
The object that will reach the bottom of the ramp first is the hollow sphere.
The reason is that the hollow sphere has the lowest rotational inertia of the four objects. Rotational inertia is a measure of an object's resistance to changes in its rotation. Objects with lower rotational inertia will accelerate faster when a torque is applied.
In this case, as the objects roll down the ramp, frictional forces between the rollers and the ramp apply a torque that causes the objects to rotate. The objects with lower rotational inertia will experience greater angular acceleration from this applied torque and will roll faster.
The rotational inertia of an object depends on its mass distribution. A hollow object has more of its mass distributed farther from its central axis, giving it lower rotational inertia compared to a solid object of the same mass and size.
So among the options given:
The hollow sphere has the lowest rotational inertia and will roll fastest.
The solid sphere has the highest rotational inertia and will roll slowest.
The solid and hollow disks will roll in between the spheres, with the hollow disk reaching the bottom before the solid disk.