Answer:
Cold to hot.
Explanation:
Heat can never flow from cold to hot, heat transfers itself from hot to cold.
Answer:
when a person is not breathing
Explanation:
The electrocardiogram shows the cardiac action of the heart as a means of the sinusoidal waves. However, the waves have a different structure as they show the pumping phase, breathing and the resting phase of the heart. The waves continues to be displayed as long as there is systolic and diastolic pressure in the heart muscles. When there is no action, such as the cessation of brain activity, action ceases.
A conductor would be any material that has the ability to permit electric current to flow through it. These materials are commonly used in electrical and electronics industries. On the other hand, an insulator would be materials having little to no conductivity and primarily used in electrical safety gears.
Question:
A 63.0 kg sprinter starts a race with an acceleration of 4.20m/s square. What is the net external force on him? If the sprinter from the previous problem accelerates at that rate for 20m, and then maintains that velocity for the remainder for the 100-m dash, what will be his time for the race?
Answer:
Time for the race will be t = 9.26 s
Explanation:
Given data:
As the sprinter starts the race so initial velocity = v₁ = 0
Distance = s₁ = 20 m
Acceleration = a = 4.20 ms⁻²
Distance = s₂ = 100 m
We first need to find the final velocity (v₂) of sprinter at the end of the first 20 meters.
Using 3rd equation of motion
(v₂)² - (v₁)² = 2as₁ = 2(4.2)(20)
v₂ = 12.96 ms⁻¹
Time for 20 m distance = t₁ = (v₂ - v ₁)/a
t₁ = 12.96/4.2 = 3.09 s
He ran the rest of the race at this velocity (12.96 m/s). Since has had already covered 20 meters, he has to cover 80 meters more to complete the 100 meter dash. So the time required to cover the 80 meters will be
Time for 100 m distance = t₂ = s₂/v₂
t₂ = 80/12.96 = 6.17 s
Total time = T = t₁ + t₂ = 3.09 + 6.17 = 9.26 s
T = 9.26 s