Electric Current in Conductors — Physics STD 11 Science — Question

A bolt of mass 0.3kg falls from the ceiling of an elevator moving down with an uniform speed of 7ms^-1. It hits the floor of the elevator (length of the elevator = 3m) and does not rebound. What is the heat produced by the impact? Would your answer be different if the elevator were stationary?

A particle is in linear simple harmonic motion between two points, A and B, 10cm apart. Take the direction from A to B as the positive direction and give the signs of velocity, acceleration and force on the particle when it is:
At the end B.

A body of mass 2kg initially at rest moves under the action of an applied horizontal force of 7N on a table with coefficient of kinetic friction = 0.1. Compute the:
Change in kinetic energy of the body in 10s.

A screw gauge has a pitch of 1.0mm and 200 division on the circular scale. Is is possible to increase the accuracy of the screw gauge by increasing the number of divisions on the circular scale?

One often comes across the following kind of statement concerning circular motion. A particle moving uniformly along a circle experiences a force directed towards the centre and an equal and opposite force directed away from the centre. The two forces together keep the particle in equilibrium. Explain, what is wrong with this statement?

Why does a child in a merry-go-round press the side of his seat radially outwards?

When is sum of two vectors always maximum and when is it minimum?

Crystalline solids are called true solids. Why?

A vessel is filled with a mixture of two different gases. Will the mean kinetic energy per molecule of both the gases be equal?

Write the work energy theorem.