Physics
Identify the correct statement from the following :
The average speed of a body can be zero even if it's average velocity is not zero.
Speed and velocity both are scalar quantities.
The magnitude of velocity of a body in motion is its speed.
Speed and velocity can be positive or negative depending upon the direction of motion.
Answer
The magnitude of velocity of a body in motion is its speed
Reason —
(1) Incorrect — Average speed is the total distance travelled divided by time, and is never zero unless the body doesn’t move at all. On the other hand, average velocity can be zero if the displacement is zero (like in a round trip).
(2) Incorrect — Speed is a scalar quantity, but velocity is a vector quantity as it has both magnitude and direction.
(3) Correct — The magnitude of velocity is the same as the speed of the body.
(4) Incorrect — Speed is always positive or zero (since it's a scalar quantity) but velocity can be positive or negative depending on the direction.
Related Questions
The value of g is maximum at:
- Tropic of capricorn
- Equator
- Tropic of cancer
- Poles
A body when projected up with an initial velocity u goes to a maximum height h in time t and then comes back at the point of projection. The correct statement is —
- The average velocity is 2h/t
- The acceleration is zero
- The final velocity on reaching the point of projection is 2u
- The displacement is zero
State whether the following quantity is a scalar or vector?
(a) Pressure
(b) Force
(c) Momentum
(d) Energy
(e) Weight
(f) Speed