Positive - Friction allows us to create heat in a desperate situation, like being lost in the woods. If we didn't have friction, we would probably freeze to death.
Negative - Friction can also cause unwanted fires, such as forest fires. If friction didn't exist, we wouldn't have these.
Answer
given,
F₁ is horizontal = 40 N
F₂ is normal = 20 N
F₃ is parallel = 30 N
work done by
W₂ = 0 as force is acting perpendicular to the direction of motion.
as the motion moved to 0.8 cm
W₃ = F₃ x d
W₃ = 30 x 0.8
W₃ = 24 J
W₁ = F₁ x d
W₁ = F₁ cos ∅ x d
W₁ = 40 cos 30⁰ x 0.8
W₁ = 27.21 J
Answer:
48.7°C
Explanation:
Step one:
given data
Quantity of heat = 4000J
mass of sample= 70g= 0.07kg
initial temperature T1=35°C
Water has a specific heat capacity of 4182 J/kg°C
Required
The final temperature T2
Step two:
Q= mcΔT
4000= 0.07*4182(T2-35)
4000=292.74(T2-35)
4000=292.74T2-10245.9
collect like terms
4000+10245.9=292.74T2
14245.9= 292.74T2
divide both sides by 292.74
T2= 14245.9/ 292.74
T2=48.7°C
Answer:
vaporization ,( Evaporation)
