Question

The minimum and maximum velocities of a projectile are 10m/s and 20m/s respectively.
The horizontal range and maximum height are respectively

Answer 1

A projectile has always a constant velocity along the horizontal direction.  At the time t=0, the projectile has the maximum speed vertically.  At the maximum height the projectile has minimum (0) vertical speed.

Ф = angle of projection
So minimum speed = u CosФ = 10 m/s

Maximum speed = u = 20 m/s
So Cos Ф = 10/20 = 1/2     =>   Ф = 60°

Horizontal range = R = u² Sin2Ф / g = 20² Sin120° / 10
         R = 20 √3 m

Maximum height = H = u² Sin²Ф /2g = 20² (3/4) /2*10
      H = 15 m

Answer 2

Answer: Hey dude answer is Range=20m and H maximum=15m

See the attachment for explanation

Explanation: