If the substance doesn't change chemically, it is a physical reaction.
Answer:
Explanation:
Given
Car speed decreases at a constant rate from 64 mi/h to 30 mi/h
in 3 sec
we know acceleration is given by 
negative indicates that it is stopping the car
Distance traveled
s=63.038 m
The answer is False. Simple machines are divided into three main categories, and not two. They are Levers, inclined planes and Pulleys. <span>These three simple machines all change force in such a way that it makes it easier for us to move an object. </span>
Answer:
Explanation:
Given that
Emissivity of surfaces(∈) = 1
We know that heat transfer between two surfaces due to radiation ,when both surfaces are black bodies
So now by putting the values
So rate of heat transfer per unit area
Answer:
F= 0
Explanation:
This exercise we use Newton's second law,
F = m a
in this case as the speed is constant the acceleration is zero therefore the force is zero.
Change we can solve it using Newton's first law, which states that every vehicle remains still or with constant speed if there is no extensive outside acting on it
We see that with any of the two forms the sum of the applied forces is zero
∑ F = 0
