Question

7. (15 pts.) A ball is thrown directly downward, with an initial speed of 10.0 m/s, from a height of 50.0 m. After what time interval does the ball strike the ground?

Answer 1

Given initial velocity, u = 10 m/s

final velocity, v = 0 m/s

diplacement coverd(height), s = 50 m

we have to find time taken, t=?

From equation of linear motio,

s = ut + (1/2) gt^2

> 50 m= 10t+0.5*(9.8m/s)*t^2

> 50m = 10t + 4.9t^2

Solving for t,

t = 2.333 s or - 4.38 s.

negative time doesnt exist so,

t =2.33 seconds ....answer.

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