Question

A football player kicks a ball at ball at an angle of 30 ^(0) with the horizontal with an initial speed of 20 m//s. Assuming that the ball travels in a vertical plance, calculate (a) the time at which the ball reaches the highest point (b) maximum height reached (c ) the horizrontal range of the ball (d) the time for wich the ball is in air. g =10 m//s^(2).

Answer 1

Answer:

a) 1 s

b) 5 m

c) 20√3 m

d) 2 s

Explanation:

a)

Time taken to reach maximum height = Half of time of flight.

= (2usinθ/g)/2

= usinθ/g

=(20 x 1/2)/10

= 1 s

b) Max. Height = u²sin²θ/2g

= (400 x 1/4)/(2x10)

=5 m

c) Range = u²sin2θ/g

= 400.(√3/2)/10

=20√3 cm

d) Time of flight = 2usinθ/g

=(2 x 20 x 1/2)/10

= 2 s