There are no correct descriptive statement on the list you included.
Object B is positively charged, Object C is negatively charged, Object D is negatively charged.
Answer
speed of the molecules
s₁ = v t
when velocity is doubled
s₂ = (2 v)t
= 2 s₁
they will hit the wall of container two times as often.
the momentum of molecule
p₁ = mvr
p₂ = m(2v)r = 2(mvr)
= 2 p₁
the momentum change is two times as great.
force is change in momentum
Δp = F(Δt)
mv-(-mv) = 2 mv

F α v
therefore average force impart to the wall on each collision is two times


p α v²
here the velocity is doubled it means pressure becomes four times.
Answer:
The correct option is;
(c) 64W
Explanation:
Here we have the Coefficient Of Performance, COP given by

The heat change from 23° to 6°C for a mass of 10 kg/h which is equivalent to 10/(60×60) kg/s or 2.78 g/s we have
= m·c·ΔT = 2.78 × 4.18 × (23 - 6) = 197.39 J
Therefore, plugging in the value for
in the COP equation we get;
which gives

Since we were working with mass flow rate then the power input is the same as the work done per second and the power input to the refrigerator = 63.674 J/s ≈ 64 W.
The power input to the refrigerator is approximately 64 W.