Answer:
(a) 2.5 m/s
(b) 37.5 KJ
Explanation:
(a)
From the law of conservation of momentum, Initial momentum=Final momentum

and making
the subject then
and since
is initial velocity of car, value given as 4 m/s,
is the initial velocity of the three cars stuck together, value given as 2 m/s and
is the final velocity which is unknown. By substitution

(b)
Initial kinetic energy is given by

Final kinetic energy is given by

The energy lost is given by subtracting the final kinetic energy from the initial kinetic energy hence
Energy lost=350-312.5=37.5 KJ
Answer:
The answer is
<h2>270 m</h2>
Explanation:
To find the distance when given the velocity and time we use the formula
<h3>distance = velocity × time</h3>
From the question
velocity of the ball = 18 m/s
time = 15 s
So the distance is
distance = 18 × 15
We have the final answer as
<h3>270 m</h3>
Hope this helps you