Question

A 100g object begins falling from a height of 5 meters. If g, the acceleration of gravity, is 10 m/s2, how long do you calculate it will be before the object reaches the ground? (Recall the formula for distance with constant acceleration from zero speed is ½at2.) 0.5 s 1.0 s 5.0 s 10 s 50 s

Answer 1

The correct option is b: 1.0 s.

Step-by-step explanation:

To find the time (t) at which the object reaches the ground we need to use the next equation:

`y_(f) = y_(0) + v_(0)t - (1)/(2)gt^(2)` (1)

Where:

`y_(f)`: is the final height = 0

`y_(0)`: is the initial height = 5 m

`v_(0)`: is the initial speed = 0 (it falls from rest)

g: is the gravity = 10 m/s²

By entering the above values into equation (1) we have:

`0 = 5m - (1)/(2)10 m/s^(2)t^(2)`

`t = \sqrt{(2*5 m)/(10 m/s^(2))} = 1 s`

Therefore, the correct option is b: 1.0 s.

I hope it helps you!