Q. A projectile is fired from the surface of the earth with a velocity of 5 $ms^{-1}$ and angle θ with the horizontal. Another projectile fired from another planet with a velocity of 3 $ms^{-1}$ at the same angle follows a trajectory which is identical with the trajectory of the projectile fired from the earth. The value of the acceleration due to gravity on the planet is (in $ms^{-2}$) is : (given g = 9.8 $ms^{-2}$)
A) 3.5
B) 5.9
C) 16.3
D) 110.8
Explanation
[Solution] Identical trajectory means the same $\frac{u^2}{g}$: $g' = 9.8 \times \frac{9}{25} = 3.5$ $ms^{-2}$. Answer (1).
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.