Answer:
a)η = 69.18 %
b)W= 1210 J
c)P=3967.21 W
Explanation:
Given that
Q₁ = 1749 J
Q₂ = 539 J
From first law of thermodynamics
Q₁ = Q₂ +W
W=Work out put
Q₂=Heat rejected to the cold reservoir
Q₁ =heat absorb by hot reservoir
W= Q₁- Q₂
W= 1210 J
The efficiency given as



η = 69.18 %
We know that rate of work done is known as power


P=3967.21 W
The magnitude of the average impulsive force imparted to the ball if it is in contact with the bat is 6000 N
The mass of the baseball, m = 0.15 kg
The speed at which it moves, v = 30 m/s
Time at which the baseball was in contact with the bat, t = 0.75 ms
t = 0.75/1000 s
t = 0.00075 s
The impulsive force is given by the formula:

Substitute m = 0.15 kg, v = 30, and t = 0.00075s into the formula above:

The magnitude of the average impulsive force imparted to the ball if it is in contact with the bat is 6000 N
Learn more here: brainly.com/question/25892144
When we set something down on the ground, the kind of work that our arms doing is : negative apex
It's happen whenever we do works that are align with the force of Gravity (to the bottom)
hope this helps