Question

A ball is thrown vertically upwards with a speed 68 m/s.The distance travelled by the ball in the seventh second is
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Answer 1

476 metre

1. speed of the ball equals to 68 metre per second
2. time is equals to 7
3. distance equal to 68 into 7 equals to 476

Answer 2

Answer:

The distance travelled by the ball in the seventh second is 3m.  

Explanation:

Given a ball is thrown vertically upwards with a speed, $u=68 m/s$.

For a body moving vertically upwards, acceleration is $g=-10m/s^{2}$

From equation of motion, the distance travelled by a body in nth second is

$S_{n} =u+\frac{1}{2} a(2n-1)$

Substituting the values,

$S_{7} =68+\frac{1}{2}\times (-10)(2\times 7-1)$

$=68-5\times 13$

$=68-65=3m$

Therefore, the distance travelled by the ball in the seventh second is 3m.