Question

A boy thrown a ball a mass 300gm with a velocity 25 m/s at an angle of 40 degree with the horizontal what is Kinetic energy of ball and heighest point on the trajectory​

Answer 1

Answer:

23.54 J

Explanation:

At highest position, occurs only horizontal component of velocity

e.g., V = ucosθ, here θ is the angle of inclination of initial velocity with horizontal

So, V = 20 cos40°

Know, kinetic energy = 1/2 mV²

= 1/2 × (200/1000) kg × {20cos40°}² J

= 1/2 × 0.2 × 400cos²40° J

= 0.1 × 400 × 0.586 [ ∵ cos²40° = 0.586 ]

= 40 × 0.586 J

= 23.54 J