Question

A body is propelled straight up with an initial velocity of $500$ ft/sec in a vacuum with no air resistance. How long will it take the body to return to the ground ( in seconds)?

• A. $21.25$
• B. $31.25$
• C. $35.25$
• D. $25.25$

Answer 1

The correct option is B $31.25$

The initial velocity is $v=500$ ft/sec , which is equal to $v=152.4$ m/sec

Time taken to reach the maximum height is $\frac{v}{g}$

Time taken to reach the ground from maximum height is $\frac{v}{g}$

Total time taken is $\frac{2v}{g}=\frac{304.8}{9.8}=31.25$

Therefore option $B$ is correct