Question

A toy rocket is launched with an initial velocity of $12.0m/s$ in the horizontal direction of from the roof of a $37.0m$ tall building. The rocket's engine produces a horizontal acceleration of $2.2m/s^2$ , in the same direction as the initial velocity, but in the vertical direction the acceleration is $9.8m/s^2$ , downward. Air resistance can be neglected. How long is the rocket in the air before it hits the ground? (in s)

• A. $2$
  
• B. $2.7$
  
• C. $2.8$
  
• D. $2.9$
  

Answer 1

The correct option is B $2.7$

Time for which rocket will be in air$=\sqrt{\frac{2h}{g}}$$=\sqrt{\frac{2\times 37}{9.8}}=2.7s$

Hence correct answer is option $B$