Answer:
Efficiency = 52%
Explanation:
Given:
First stage
heat absorbed, Q₁ at temperature T₁ = 500 K
Heat released, Q₂ at temperature T₂ = 430 K
and the work done is W₁
Second stage
Heat released, Q₂ at temperature T₂ = 430 K
Heat released, Q₃ at temperature T₃ = 240 K
and the work done is W₂
Total work done, W = W₁ + W₂
Now,
The efficiency is given as:

or
Work done = change in heat
thus,
W₁ = Q₁ - Q₂
W₂ = Q₂ - Q₃
Thus,

or

or

also,

or

thus,

thus,

or

or
Efficiency = 52%
Speed is constant. 50 miles = 1 hour. 600/50 = 12. 1hr(12) = 12 hours.
Answer:
628.022466 N
8.61 m/s
Explanation:
m = Mass
= Coefficient of friction
t = Time taken
u = Initial velocity
v = Final velocity
s = Displacement
a = Acceleration
g = Acceleration due to gravity = 9.81 m/s²

Magnitude of frictional force is 628.022466 N


Initial speed of the player is 8.61 m/s
Steel is more elastic than rubber<span> because </span>steel<span> comes back to its original shape faster </span>than rubber<span> when the deforming forces are removed, hope it helps :)</span>
Think of the formula force=mass x acceleration. even though they have the same acceleration, a train has more mass. is that helpful?