An example is when u rub your pen on your hair hard that is friction
Answer:
450 kJ
Explanation:
Q = mCΔT
where Q is heat (energy),
m is mass,
C is specific heat capacity,
and ΔT is the temperature change.
Q = (1.2 kg) (4180 J/kg/°C) (100°C − 10°C)
Q = 451,440 J
Q ≈ 450 kJ
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
Answer:
Explanation:
We shall convert all the displacement in vector form .
i and j represents east and north respectively .
D₁ = 4 i
D₂ = 4 j
D₃ = - 5 cos 53.1 i + 5 sin 53.1 j
= -3i + 4 j
Total displacement = D₁ + D₂ + D₃
= 4i + 4 j - 3i + 4 j
= i + 8j
magnitude of displacement = √( 1² + 8² )
= 8.06 km
velocity = 8.06 / 5
= 1.61 km / h
Direction from x axis in anticlockwise direction .
Tanθ = 8 / 1 = 8
θ = 83° north of east .