When you bring two objects of different temperature together, energy will always be transferred from the hotter to the cooler object. The objects will exchange thermal energy, until thermal equilibrium is reached, i.e. until their temperatures are equal. We say that heat flows from the hotter to the cooler object. Heat is energy on the move.
Units of heat are units of energy. The SI unit of energy is Joule. Other often encountered units of energy are 1 Cal = 1 kcal = 4186 J, 1 cal = 4.186 J, 1 Btu = 1054 J.
Without an external agent doing work, heat will always flow from a hotter to a cooler object. Two objects of different temperature always interact. There are three different ways for heat to flow from one object to another. They are conduction, convection, and radiation.
Answer:

Explanation:
Average velocity is defined as the ratio of total displacement of the motion and total time taken in that motion
here we know that initially the sky diver drops without opening parachute by total displacement 625 m
then she open her parachute and drop another 362 m
so first it took time t = 15 s to drop without open parachute
then it took t = 139 s to drop next displacement
so here total displacement is given as

total time is given as

so average velocity is given as


<span>the overload principle hope this helps
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Answer:
Work done by the gardner is 500 J
Explanation:
As we know that the gardner apply force perpendicular upward by magnitude 300 N and along the floor horizontal force is 100 N
so we have

now the displacement of the gardner along the floor is

now work done is given as

so we have


Average speed (v) = total distance(d) / total time (t)
d = 57 + 87km = 144km
t = 2 + 3hrs = 5hrs
v = d÷t = 144÷5 = 28.8km/hr