Question

the hoover dam is 725 feet tall. how long would it take an object to fall from the top to the base of the dam? round the answer to two decimal places

Answer 1

Answer:

45.05 seconds

Step-by-step explanation:

Use the formula: d = v$i$ t + $\frac{1}{2}$ a$t^{2}$

d = distance      v$i$ = initial velocity (m/s)    

t = time (s)     a = acceleration (m/$s^{2}$)

m is meters and s is seconds. They are units of measurement so leave them be.

Assuming the object is simply dropped, the initial velocity is 0 since the object was not moving before it was dropped.

The distance is 725 feet, which is 220.98 meters.

The acceleration is 9.81m/$s^{2}$ since that is the acceleration of Earth's gravity, aka free fall.

Time is what we are trying to find so just leave it as the variable t.

So plug the values into the equation:

220.98m = (0)(t) + $\frac{1}{2}$ (9.81m/$s^{2}$)(t)

220.98m = (4.905m/$s^{2}$)(t)

45.0519877676s = t

t = 45.05s

Remember to pay attention to units because your answer will be wrong otherwise