Question

Categorize the following motion as being either an example of +ve or –ve acceleration.

i. Moving in the +ve direction and speeding up = _____________

ii. Moving in the +ve direction and slowing down = ______________

iii. Moving in the -ve direction and speeding up = ______________

iv. Moving in the -ve direction and slowing down = _______________

• A. +ve , -ve , +ve , -ve
• B. +ve , +ve , -ve, -ve
• C. +ve , -ve , -ve , +ve
• D. –ve , +ve , -ve , +ve

Answer 1

The correct option is C

+ve , -ve , -ve , +ve

We know that,

$a=\left(\frac{v_f-v_i}{t}\right)$

For speeding up, magnitude wise $v_f>v_i$ and for slowing down, $v_i>v_f$

Moreover, velocity is negative if moving in negative direction and vice versa.

Substituting these values, we get acceleration as +ve, -ve, -ve and +ve respectively for the four cases.