A ball is thrown with a velocity of 20 m/s at an angle of 60 degrees above the horizontal. What is the horizontal component of its instantaneous velocity at the the exact top of its trajectory?

Answer: 10 m/s.

Explanation:

Assuming no air resistance, horizontal component of its velocity will be constant throughout the motion of 10 m/s.

Formula is,

Let horizontal component of velocity be hv.

Now,

cos (60) = hv / 20.

hv = 20 * cos (20)

hv = 10 m/s.