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
♥ If the wind is strong enough it can do so.
♥ By having a strong enough wind you can blow out the fire before the flame can consume any more vapor.
♥ If the wind is fast enough, like a birthday cake candle for example, the wind will burn out.
Answer:
B
Explanation:
The control is something that is meant to not be changed, the control is a comparison of the experimental.
ionic compound. The atom that lost the electron becomes a cation, and the atom that gains an electron becomes an anion. The cation and anion bond together because they have opposite charges to form an ionic compound. The question may be looking for just cation or anion, though.