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# An orange falls from a height of 20m. How long does it take to reach the ground?

### Question

An orange falls from a height of 20m. How long does it take to reach the ground?

A) 2.0 sec

B) 0.5 sec

C) 1 sec

D) 4 sec

### Explanation:

$$s = ut + \frac{1}{2}gt^2$$
s = 20m, u = 0, t = ?
g = 10m/s$$^2$$
20 = 5t$$^2$$
t$$^2$$ = \cfrac{20}{5} = 4
t$$^2$$ = 4
t = $$\sqrt{4}$$
t = 2secs

## Dicussion (1)

• $$s = ut + \frac{1}{2}gt^2$$
s = 20m, u = 0, t = ?
g = 10m/s$$^2$$
20 = 5t$$^2$$
t$$^2$$ = \cfrac{20}{5} = 4
t$$^2$$ = 4
t = $$\sqrt{4}$$
t = 2secs