Acar rolls off a horizontal cliff 125 meters high, and lands 100 meters from the base of the cliff. how fast was the car moving when it rolled off the cliff?

19.81m/s

Explanation:

To find the speed at which the car leaves the cliff, first we need to know how long it took to reach the ground. We do this with the equation:

Where is the vertical position at a time , since we are looking for the moment when the car reaches the gound: . is the initial vertical position, in this case the height of the cliff: . is gravitational acceleration: .

So replacing the known values:

and since we need the time, we clear for it:

At time the car  reaches the gound, according to the problem at a horizontal distance from the base of the cliff of 100m.

To find the velocity we use:

where is the horizontal distance at time (in this case and  ), is the initial horizontal distance, we define the cliff as zero in horizontal distance so , and is the velocity of the car when it rolled of the cliff.

replacing the known values:

and we clear for :

The initial velocity (when it rolled of the cliff) is 19.81m/s

a.) travels faster in solids because the particles are closer together.

air is a gas water is a liquid