Question

An astronaut on the moon drops a rock from rest. The rock falls 0.8m in one second of falling time. If the dropped rock fell for a total of two seconds of time instead of 1 second, then the distance traveled would be:____.

A) The same.
B) Doubled.
C) Tripled.
D) Quadruple.
E) None of the above.

Answer 1

D) Quadruple.

Step-by-step explanation:

We will use the second equation of motion to solve this problem:

`s = v_it + (1)/(2)gt^2`

where,

s = distance travelled by the rock

vi = initial speed of rock = 0 m/s

t = time taken

g = acceleration due to gravity on the surface of the moon

Therefore,

`s = (0\ m/s)t+(1)/(2)gt^2\\\\s =(1)/(2)gt^2`----------- equation (1)

Now, we double the time:

`s' = (1)/(2)g(2t)^2\\\\s' = 4((1)/(2)gt^2)`

using equation (1):

s' = 4s

Hence, the correct option is:

D) Quadruple.