Question

Choose the wrong statement.
(a) The accelerated motion may be due to change in magnitude of velocity or direction of velocity or both
(b) The velocity and acceleration of a body may not necessarily be in the same direction
(c) The velocity and acceleration of a body may not be zero simultaneously
(d) When a body falls freely under the action of gravity, its acceleration is zero

Answer 1

Hint : Acceleration and velocity both are vector quantities and have direction of the motion. In this question, we have to use the definitions and properties of velocity and acceleration to find the correct option.

Complete step by step solution: Since acceleration is a vector quantity that depends on the rate of change of velocity and the direction of change, speed can be caused by a change in velocity or direction of velocity, or both.
Hence, acceleration depends either on change in magnitude of velocity i.e. speed or change in direction of the velocity.

Thus, option A is correct.

Additional Information: Acceleration is the name we give to any process where the velocity changes. Since velocity is a speed and a direction, you have only two ways to accelerate: change your speed or change your direction — or change both.
If we are not changing our speed and we are not changing our direction, we cannot just accelerate - no matter how fast you are moving. So, a jet traveling with a constant velocity at a speed of 800 mph along a straight line has zero acceleration, even if the jet is moving really fast, because the velocity is not changing. When the jet lands and quickly comes to a stop, it will have acceleration as it slows down.

Note: Acceleration a, is equal to the difference between the initial and final velocities. The negative acceleration is called retardation/deceleration.
The equations of motion can be applied only when acceleration of the body is constant. When a body falls from a Height h, under gravity, then u= 0 and a= +g, S= h.