Gravitation — Physics STD 11 Science — Question

Figure below shows four different spring arrangements. If the mass in each arrangement is displaced from its equilibrium position and released, what is the resulting frequency of vibration in each case? Neglect the mass of the spring. (Fig. (a) and (b) represent an arrangement of springs in parallel, and (c) and (d) represent springs in series)

Two small bodies of masses 10kg and 20kg are kept a distance 1.0m apart and released, Assuming that only mutual gravitational forces are acting, find the speeds of the particles when the separation decreases to 0.5m.

A source and an observer are approaching one another with velocity 4m/s. If the true frequency is 1200Hz, deduce the observed frequency under the following conditions:

1. All velocity is in the source alone.
2. All velocity is in the observer alone.

Take the velocity of sound waves in air to be 340ms^-1.

Indium antimonide has a band gap of 0.23eV between the valence and the conduction band. Find the temperature at which kT equals the band gap.

A football is kicked into the air vertically upwards. What is its

1. acceleration, and
2. velocity at the highest point?

State three basic laws of motion. Show that the first law of motion gives the definition of force and the second law of motion gives the measure of force.

An engine is attached to a wagon through a shock absorber of length 1.5m. The system with a total mass of 50,000kg is moving with a speed of 36km h^-1 when the brakes are applied to bring it to rest. In the process of the system being brought to rest, the spring of the shock absorber gets compressed by 1.0m. If 90% of energy of the wagon is lost due to friction, calculate the spring constant.

Two cars A and B are running at velocities of 60km/ hr and 45km/ hr respectively. Calculate the relative velocity of car A if:

1. They are both travelling eastwards.
2. Car A is travelling eastwards and car B is travelling westwards.