Hooke S Law

Speed of sound
Also
So

Since force in both springs is same: If then Work Hence, work by second spring is greater than first

Gravity first causes spherical ball to fall with increasing speed, but as it speeds up backward dragging force i.e. viscous force increases. Eventually the viscous force is enough to balance the force of gravity, so the acceleration stops and the sphere reaches a constant terminal velocity.

From Hooke's law, Young modulus
The Strain produced in a perfectly rigid body is zero
i.e Strain


Thus the Young's modulus of perfectly rigid body material is infinite.