If an object is dropped, how fast will it be moving after #4s#?

1 Answer
Apr 16, 2016

Answer:

#39.2m/s#

Explanation:

If an object is dropped, the major force acting on it is gravity. We mostly ignore smaller variables like air resistance. The acceleration of gravity downwards is about #9.8ms^-2#.

Acceleration is how much velocity (#m/s#) changes by the second, so the units for acceleration are #(m/s)/s# or #m/s^2#, which is also written mathematically as #ms^-2#.

If we have four seconds of movement, then multiply that by the acceleration and it will give you the velocity.

#9.8m/s^2 * 4s = 39.2(m*s)/s^2 = 39.2m/s#