Motion in a Str...

Assertion: The average and instantaneous velocities have same value in a uniform motion
Reason: In uniform motion, the velocity of an object increases uniformly.

Assertion: Rocket in flight is not an illustration of projectile.
Reason: Rocket takes flight due to combustion of fuel and does not move under the gravity effect alone.

Assertion: The position-time graph of a body moving uniformly is a straight line parallel to position-axis
Reason: The slope of position-time graph in a uniform motion gives the velocity of an object.

Assertion: Position-time graph of a stationary object is a straight line parallel to time axis
Reason: For a stationary object, position does not change with time.

Assertion: The slope of displacement-time graph of a body moving with high velocity is steeper than the slope of displacement-time graph of a body with low velocity
Reason: Slope of displacement-time graph = Velocity of the body

Assertion: Distance -time graph of the motion is a straight line inclined uniformly accelerated motion is a straight line inclined to the time axis
Reason: Distance travelled by a body having uniformly accelerated motion is directly proportional to the square of the time taken.

Assertion: A body having non-zero acceleration cam have a constant velocity.
Reason: Acceleration is the rate of change of velocity

Assertion: A body, whatever its motion is always at rest in a frame of reference which is fixed in the body itself.
Reason: The relative velocity of a body with respect to itself is zero.

Assertion: Displacement of a body may be zero when distance travelled by it is not zero
Reason: The displacement is the longest distance between initial and final position.

Assertion: The equation of motion can be applied only if acceleration is along the direction of velocity and is constant .
Reason: If the acceleration of a body is constant then its motion is known as uniform motion.