♪⚝Sanjiv❀Jaiswal❁⩸

Suppose two wires of steel and rubber of equal length L and cross-section A are stretched by the same force F. The Young modulus for steel is steel steel and similarly that for rubber iswhere l_steelis the extension of the steel wire and l_rubberis that of the rubber wire. Thus taking the ratio, we have



As l_rubber> l_steel, Y_steel> Y_rubber. The more the value of the elastic constant, the more the object is elastic because a very large force or stress is needed to make it break. This means...

For a stable equilibrium of a body, its center of gravity should lie as low as possible. Loading heavy loads first in a truck and loading light loads on the heavy ones can lower the center of gravity of the truck and load system. This ensures the stability of the system and the loads can be transported safely. Therefore the heavier loads must be loaded first in any transporting vehicles. For the same reason, the passengers are not allowed to stand in a boat and the bottom of a ship is made...

A ball thrown straight up has zero velocity at its highest point instantly. The ball is not in equilibrium at this point because it is always acted upon by the force of gravity and has acceleration. If it had gained zero acceleration at its highest point, it would have been in equilibrium.

When a man carries a bucket full of water on his right hand without leaning towards his left, the location of the center of gravity of the system (man + bucket full of water) changes and the system becomes unstable. This produces a net torque about the center of gravity of the man and this torque tries to rotate the man to the right. In order to cancel this torque, the man has to lean to the left so that the center of gravity of the man and the bucket full of water as a whole lies within the...

When we use two fingers to open the cap of a bottle, we apply the torque due to a couple which is the product of one force and the perpendicular distance between the forces, i.e., a distance equal to the diameter of the bottle neck. When we use one finger to open it, we apply the torque which is the product of the force and the distance equal to its radius. So the former torque is twice the latter torque and hence it is easier to open the cap of the bottle with two fingers than that with one...

The torque T produced by applying a force F at a distance r from the axis of rotation is T = rF. It follows from this equation that the distance r should be increased in order to increase the torque. Since the force is applied to the handle put near the circumference of the stone, the distance r is the greatest. For this reason, the greater amount of torque can produce a larger angular acceleration. In such a hand driven grinding machine, grains are ground comfortably

Breaking stress may occur when the material is excessively stretched or compressed. To withstand the heavy weight of an elephant, it has thicker legs so that the ratio of the weight to the cross-section area of the legs does not exceed the breaking stress of the bone material. To withstand the weight of a man, he can have thin legs and the ratio of his weight to the cross-section area of the leg will not exceed the breaking stress for the bone material. This is why an elephant has thicker...