Energy can change forms and be transferred.
Answer
given,
mass of the crate = 53 Kg
force applied by the worker = 180 N
Angle made with the horizontal = 35°
crate moves = 2.9 m
a) The work done equals the force in the direction of the displacement, times the displacement
W = F_x ×d
W = 180 cos 35° × 2.9
W = 427.6 J
b) A force that is perpendicular to the direction of the displacement does not do any work so work done by gravitational force is zero
c) Similarly for the normal force the work done will be zero.
d) Total work done by the crate is equal to 427.6 J
These forces will slow the object down unless there is no gravity acting on it.
Answer:
32%
Explanation:
For a heat engine, efficiency is work out divided by heat in:
η = Wₒ / Qᵢ
Since energy is balanced, heat in is the sum of work out and heat out:
Qᵢ = Wₒ + Qₒ
Therefore:
η = Wₒ / (Wₒ + Qₒ)
Given Wₒ = 710 J and Qₒ = 1480 J:
η = 710 / (710 + 1480)
η = 0.32
The thermal efficiency is 32%.
