Answer:
Wouldn't it be 17.5. Force doubles in weight.
Explanation:
Answer:
In thermodynamics, heat is transferred energy that moves between substances or systems because of their temperature difference. According to the first law of thermodynamic and the law of energy conversion s a form of energy, heat is cannot be created or destroyed only moves from one form to other.
The stone gets heat energy from fire and moves this heat energy or thermal energy to water as it cools off and the water warms up. Heat moves or is transferred spontaneously from the hot stone into the cold water. Eventually, the stone and water have the same temperature and water becomes heated. At the time of heat flowing out of the stone into the water, the heat energy became less ordered, due to spreading out through both the stone and the water. This is a net increase in entropy which is the second law of entropy.
Answer:
Friction produces unnecessary heat leading to the wastage of energy. The force of friction acts in the opposite direction of motion, so friction slows down the motion of moving objects. Forest fires are caused due to the friction between tree branches. However, friction can also cause problems in a car. Friction between moving engine parts increases their temperature and causes the parts to wear down. Friction can be both harmful and helpful, so it may be necessary to decrease or increase friction.
Observe that the given vector field is a gradient field:
Let 
, so that
Integrating the first equation with respect to 
, we get
Differentiating this with respect to 
gives
Now differentiating 
with respect to 
gives
Putting everything together, we find a scalar potential function whose gradient is 
,
It follows that the curl of is 0 (i.e. the zero vector).
Answer:
20 mins
Explanation:
To go 90 km it takes =60 mins(1 hr)
" " 1 km it takes =60/90 mins
" " 30 km it takes =60/90 multiplied by 30
= 20 mins
