7) PE= Fwh = (72 m) (966 N) = 69552 Joules 7
8) zero PE=mass*g*height
I hope it’s correct
Answer:
speed=abs(v)=40ms^-1
Explanation:
acceleration, a = (v-u)/t
since initial velocity u=0 (at rest) and a=8ms^-2,
8=v/5
hence after 5 seconds, v=40ms^-1
Because the position depends on the amount of time that has passed.
Answer:
Q₂ = 5833.33 J
Explanation:
First we need to find the energy supplied to the heat engine. The formula for the efficiency of the heat engine is given as:
η = W/Q₁
where,
η = efficiency of engine = 30% = 0.3
W = Work done by engine = 2500 J
Q₁ = Heat supplied to the engine = ?
Therefore,
0.3 = 2500 J/Q₁
Q₁ = 2500 J/0.3
Q₁ = 8333.33 J
Now, we find the heat discharged to lower temperature reservoir by using the formula of work:
W = Q₁ - Q₂
Q₂ = Q₁ - W
where,
Q₂ = Heat discharged to the lower temperature reservoir = ?
Therefore,
Q₂ = 8333.33 J - 2500 J
<u>Q₂ = 5833.33 J</u>
Potential energy = mass x acceleration due to gravity x height
= 2.5 x 9.8 x 2.2
= 53.9 J.
Hope this helps!
