A meteor burns up on entering earth’s atmosphere due to
Stmospheric pressure.
Heat of the earth.
Solar radiation.
Excessive friction.
The application of decreasing friction include
I. Ball bearing used in moving parts of a machine.
II. The streamlined shape of an aircraft.
III. The layer of air between the hull of a hovecraft and the ground.
I and II only
II and III only
III and I only
All of these
It is difficult to move a cycle with brakes on because
Rolling friction opposes motion on road
Sliding friction opposes motion on road
Rolling friction is more than sliding friction
Sliding friction is more than rolling friction
In decreasing order of magnitude which of the following is CORRECT?
rolling, static, sliding friction.
static, sliding, rolling.
static, rolling, sliding.
sliding, static, rolling.
The force required to keep an object moving with the same speed is a measure of
static friction.
sliding friction.
rolling friction.
limiting friction.
The minimum force required to make one body just slide over another body is called
Static friction.
Rolling friction.
Sliding friction.
Limiting friction.
Wheel and axle help to move objects with a very little force. This is because
Rolling friction > Sliding friction.
Sliding friction > Rolling friction.
Rolling friction = Sliding friction.
Rolling friction + Sliding friction = 0
The frictional force exerted by fluids is called
Lift.
Drag.
Dynamic friction.
If we apply a force to a body which is in contact with the surface of another body and if the body does not move, then the force of friction is
How does the proper inflation of tyre save fuel?
Normal reaction decreases
Normal reaction increases
Sliding contact with the road decreases
Sliding contact with the road increases
