Question

Statement I For a particle moving in a straight line, if the velocity is positive and acceleration is negative then it means particle is decelerating.

Statement II Negative acceleration and deceleration are the same.

• A. Statement I is True, Statement II is True; Statement II is a correct explanation for Statement I
• B. Statement I is True, Statement II is True; Statement II is not a correct explanation for Statement I
• C. Statement I is True, Statement II is False
• D. Statement I is False, Statement II is True

Answer 1

The correct option is C

Statement I is True, Statement II is False

The explanation for the Assertion statement:

1. According to the second equation of the motion, $v=u+at$. Here, $v$ is the velocity at time $t$, $u$is the initial velocity and $a$is the positive acceleration.
2. If we take acceleration as negative in this equation then the new equation is $v=u-at$
3. As $u+at>u-at$, it means the particle is decelerating

The explanation for the Reason statement:

1. Acceleration is a vector quantity and a negative acceleration indicates that the direction of the velocity of the particle is opposite to the direction of the acceleration applied to it.
2. Deceleration is a scalar quantity. If the velocity of the particle is decreasing overtime then it is said to be decelerating.

Statement I is true and Statement II is false. Hence, Option C is correct