PART - 2 CH - 8 Mechanical Properties of Solids — Physics STD 11 Science — Question

It is a common observation that rain clouds can be at about a kilometre altitude above the ground.
Rate of change of momentum is force. Estimate how much force such a drop would exert on you.

How would the period of spring mass system change, when it is made to oscillate horizontally and then vertically?

Answer the following:
An artificial satellite orbiting the earth in very thin atmosphere loses its energy gradually due to dissipation against atmospheric resistance, however small. Why then does its speed increase progressively as it comes closer and closer to the earth?

What will be the ratio of the velocity of efflux from two holes made with a separation (H - 2h) in a container holding liquid of height 'H' and one hole at a depth ‘h' from its bottom? Give reason.

Two resistors having equal resistances are joined in series and a current is passed through the combination. Neglect any variation in resistance as the temperature changes. In a given time interval:

1. Equal amounts of thermal energy must be produced in the resistors.
2. Unequal amounts of thermal energy may be produced.
3. The temperature must rise equally in the resistors.
4. The temperature may rise equally in the resistors.

The thermal energy developed in a current-carrying resistor is given by U = i² Rt and also by U = Vit. Should we say that U is proportional to i² or i?

Water flows at a speed of 6cm/s through a tube of radius 1cm. Coefficient of viscosity of water at room termperature is 0.01 poise. Calculate the Reynolds number. Is it a steady flow?

Answer the following :
The triple-point of water is a standard fixed point in modern thermometry. Why? What is wrong in taking the melting point of ice and the boiling point of water as standard fixed points (as was originally done in the Celsius scale)?

The specific heat of argon at constant volume is 0.075 kcal kg^-1K^-1, then what will be its atomic weight? [Given, R = 2 cal mol^-1K^-1]

What is the amount of work done in bringing a mass from the surface of Earth on one side to a point diametrically opposite to the other side?