Which of the following situations is possible?
(a) An object can have acceleration, but constant velocity.
(b) The velocity of an object may be zero but acceleration is not zero.
(c) Distance and the magnitude of displacement are equal in circular motion.
(d) Average speed and the magnitude of average velocity are always equal in circular motion.
Answers
Answer:
(a) The given statement is possible.
The word acceleration implies a change in the object’s velocity. One example of this is vertical particle projection. When an object is thrown upwards, the maximum height velocity of the body is zero, but the constant acceleration due to gravity is still working.
(b) The given statement is possible.
The object can move in a certain path with a perpendicular acceleration, in the case of circular motion. When an object is moving along a circular motion its path is along the circle tangent but the centripetal acceleration is towards the circle radius. We understand that with the radius, a tangent still makes a right angle. So when the object in a circular motion, the velocity and accelerations are in a mutually perpendicular direction.
Among the following, the possible situation is: Average speed and the magnitude of average velocity are always equal in circular motion.
- Acceleration is the change in velocity with respect to time. Hence, if there is an acceleration produced, there has to be a change in velocity, that is, the velocity cannot remain constant.
- Velocity is the change in position of a body with respect to time. If the velocity is zero, it means that the body is not moving, that is, the body is at rest. A body at rest has zero acceleration.
- Distance and the magnitude cannot be the equal in case of circular motion because when the body completes a revolution, the distance covered would be equal to circumference. Whereas the displacement would be zero, since the initial and final positions of the body is same.
- Average speed and average velocity would have the same magnitude as both of them have the same dimensions for calculation. Since the direction is not considered, it is possible.