Question

A body is projected vertically upward with a speed $40$ meter per second. The distance travelled by the body in the last second of upward journey is?

• A. $4.9m$
• B. $9.8m$
• C. $12.4m$
• D. $19.6m$

Answer 1

The correct option is A $4.9m$

Here,

Total time of upward motion$=\frac{u}{g}=\frac{40}{9.8}=4.08$

Velocity at $3.08s=u-gt=40-3.08\times 9.8=9.82$

Velocity at $4.08s=0$

$s=\frac{v_4^2-v_3^2}{2\times -9.8}$

$s=\frac{0^2-{9.8}^2}{2\times -9.8}$

$s=4.9m$

Option $\text{A}$ is the correct answer