The answer is D
Explanation:
Answer:
B
Explanation:
Laboratories are usually controlled: however, in public places, there are way too many factors that could change an experiment
Answer: Our body contains chemical potential energy from food we have eaten.
This chemical potential energy is transformed into the kinetic energy of our hands and arms as we rub our hands together.
As our hands move past each other and rub against each other, friction allows the kinetic energy to be transformed into thermal energy on the surface of our hands.
Explanation:
It is true that our food contains chemical bonds and these bonds have potential energy stored. So, when we eat food then our body acquires chemical potential energy.
When we rub our hands and arms then they form kinetic energy as atoms present within the skin of our hands come into motion. This rubbing of hands leads to the formation of heat which means thermal energy is being generated.
Thus, we can conclude that our body contains chemical potential energy from food we have eaten.
This chemical potential energy is transformed into the kinetic energy of our hands and arms as we rub our hands together.
As our hands move past each other and rub against each other, friction allows the kinetic energy to be transformed into thermal energy on the surface of our hands.
Answer:
The plane would need to travel at least 
(
.)
The 
runway should be sufficient.
Explanation:
Convert unit of the the take-off velocity of this plane to 
:
.
Initial velocity of the plane: 
.
Take-off velocity of the plane 
.
Let 
denote the distance that the plane travelled along the runway. Since acceleration is constant but unknown, make use of the SUVAT equation 
.
Notice that this equation does not require the value of acceleration. Rather, this equation make use of the fact that the distance travelled (under constant acceleration) is equal to duration 
times average velocity 
.
The distance that the plane need to cover would be:
.
