Answer: Heat dissipation mechanism
Explanation: Heat dissipation mechanism is a thermoregulatory response in humans whereby the hypothalamus of the brain initiates certain processes to reduce the high body temperature. Eg, sweating is initiated which helps cool down the body temperature, also superficial arteries are dilated, thereby leading to flushing and decreasing heatloss into the air. And metabolic heat production is also reduced.
Answer:
work done = 750 J
Explanation:
Given data:
Force on object = 50 N
Distance covered = 15 m
Work done = ?
Solution:
W = F. d
W = work done
F = force
d = distance
Now we will put the values in formula.
W = 50 N × 15 m
W = 750 N. m = 750 J
Answer: Statements (A), and (C) are correct.
Explanation:
The statements that are true are as follows.
- Particles in a liquid need to move more slowly in order to freeze.
When a liquid freezes the molecules get attracted towards each other. This attraction of particles occurs slowly. Hence, this statement is true.
- Attractive forces between the particles in a liquid are broken when a liquid boils.
When temperature is raised, the molecules in a liquid gains kinetic energy and start to move quickly in random directions. As a result, liquid state changes to gaseous state. Hence, this statement is true.
If the attractive force between gas molecules have to be increased, they should be moving slower instead because moving faster does not help attracting molecules together.
Hence, the statement particles in gas move fast enough to make more attractive forces when the gas condenses is not true.
Watt stands for power that is energy per unit time
