Speed of the projectile at its maximum height is only along horizontal direction
so at highest point

now when he is at half of the maximum height the speed will be in x and y direction both

here it is given that




also we know that

here we know that maximum height is given as



now from above


also we know that angle of projection is


so angle is


Answer:
5 moles of O2are required, you can see it in your equation.
Answer:
F=50kg
D=5m
W=FD
therefore work done is 250Nm
The center of mass is given with this formula:

Velocity is:

So, for the velocity of the center of mass we have:

In our case it is: