The thermal efficiency of an engine is

where
W is the work done by the engine
Q is the heat absorbed by the engine to do the work
In this problem, the work done by the engine is W=200 J, while the heat exhausted is Q=600 J, so the efficiency of the machine is
Because melting point<span> and </span>freezing point<span> describe the</span>same<span> transition of matter, in this case from liquid to solid (</span>freezing) or equivalently, from solid to liquid (melting<span>).</span>
Answer:

Explanation:
1. Find the equation of eht maximal friction force:
The maximal friction force is given by the equation
, where μs is the static friction coefficient, m is the car´s mass and g is the gravitational force.
2. Replace values in the equation to find the answer:


Answer: Hello!
Lewis is travelling at 165 mph, which means miles per hour, this says that he does 165 miles in one hour.
We want to know how much time takes to cover 16 miles.
this can be calculated as the quotient of the distance and the velocity; this is:

if we want to write this in minutes, then:
we know that one hour has 60 minutes, then 0.096 hours has:
0.096h*60mins/1h = 5.8 minutes.
then Lewis needs 5.8 minutes in order to cover 16 miles if his speed is 156 miles per hour.
Given:
Work done, W = 5 J
Initial energy = 8J
Final energy = 30J
Let's determine if the work done have a positive or nrgative value.
Appy the equation for the first lae of thermodynamics:

Where:
U is the change in internal energy
Q is the added heat
W is the work done
To find the work done here, we have:
Rewrite the formula for W

Where:
ΔU = 30J - 8J = 22J
Q = 5J
Thus, we have:

Therefore, the work done here is -17J.
This means the work done in this scenario has a negative value.
ANSWER:
The work done in this scenario has a negative value