Answer:

Explanation:
We know that from Newton's second law of motion, F=ma hence making acceleration the subject then
where a is acceleration, F is force and m is mass
Also making mass the subject of the formula 
For
and
hence 
Answer:
18min
Explanation:
v=d/t
t=d/v= 27/90 =0.3hrs =18min
The object<span> is moving with a decreasing acceleration. The </span>object<span> is moving with </span>a constant<span> velocity.</span>

The momentul of the system preserves:
Ok, we found the speed after the collision.
Now, because the impact is plastic, it produces heat, sound energy and who knows what other forms of energy. We denote all this wasted energy with

.
Now, we write the energy conservation law:

From the above equation, you find

, and then conclude that the sound energy can certainly not be greater than this.