Question

A particle is projected up with a velocity of $v_0=10m/s$ at an angle of ${\theta }_0={60}^{\circ }$ with horizontal onto an inclined plane. The angle of inclination of the plane is ${30}^{\circ }$. If the particle is projected down onto the inclined plane at same speed and angle with the inclined plane the ratio of the time of flight and time of flight for upward projection is :

Answer 1

Time of flight is given by,
$T=\frac{2u_y}{g\cos \alpha }$ Time of flight will be same in both cases, because $u_y$ is same in both cases.
Hence, ratio of time of flight for downward and for upward projection will be $1:1$.

Final answer: $\left(c\right)$