Q.71)-A cannon ball is fired. The motion of this ball is an example of
- Straight line motion
- Projectile motion
- Hperbolic motion
- Horizontal motion
Q.72)-Upward force on a floating body is called
- Jerk
- Buoyancy
- Archimedal force
- Anti-gravity
Q.73)-When a bus starts suddenly, then passengers in the bus tend to fall backwards. This event is an example of
- Inertia of rest
- Inertia of motion
- Inertia of direction
- None of these
Q.74)-Which of the following quantity is a measure of inertia?
- Velocity
- Acceleration
- Mass
- Weight
Q.75)-Friction can be reduced by which of the following? I.Polising surfaces II. Use of lubricants III. Decreasing area of contact
- Only I
- Only II
- Only I and II
- All options are correct
Q.76)-Action and reaction
- Always act on same body
- Are equal in magnitude
- Are in same direction
- Always act independently
Q.77)-Law of Inertia is also known as
- Newton's first law of motion
- Newton's second law of motion
- Newton's third law of motion
- None of these
Q.78)-Which scientist gave 'laws of motion'?
- Galileo
- Newton
- Einstein
- Boyle
Q.79)-The force acting on an object perpendicular to the surface is called
- Pressure
- Work
- Thrust
- Friction
Q.80)-Which contact force is responsible for changing the state of motion of an object?
- Magnetic force
- Frictional force
- Muscular force
- Electrostatic force