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A grade 12 Physics student shoots a basketball

from the ground at a hoop which is 2.0 m above
her release. The shot was at a velocity of 10 m/s
and at an angle of 80° to the ground.
a. Determine the vertical velocity of the ball
when it is at the level of the net. You
should get two answers.
Please show ALL steps

User Smilu
by
7.3k points

1 Answer

4 votes

Answer:

7.84 m/s

Step-by-step explanation:

Height, h = 2 m

Initial velocity, u = 10 m/s

Angle, A = 80°

(a) Let the time taken to go to the net is t.

Use second equation of motion


h = u t + 0.5 at^2\\\\- 2 = - 10 sin 80 t - 4.9 t^2\\\\4.9 t^2 + 9.8 t - 2 = 0 \\\\t= (- 9.8\pm√(9.8^2 + 4* 4.9* 2))/(9.8)\\\\t = (- 9.8 \pm 11.6)/(9.8)\\\\t = - 2.2 s , 0.2 s

Time cannot be negative.

So, t = 0.2 s

The vertical velocity at t = 0.2 s is

v = u + at

v = 10 sin 80 - 9.8 x0.2

v = 9.8 - 1.96 = 7.84 m/s

User Nishi Bangar
by
7.7k points