Metric system. important because it saves us time due to the fact that we do not have to convert our units every time.
Answer:
Explanation:
Before it hits the ground:
The initial potential energy = the final potential energy + the kinetic energy
mgH = mgh + 1/2 mv²
gH = gh + 1/2 v²
v = √(2g (H - h))
v = √(2 * 9.81 m/s² * (0.42 m - 0.21 m))
v ≈ 2.0 m/s
When it hits the ground:
Initial potential energy = final kinetic energy
mgH = 1/2 mv²
v = √(2gH)
v = √(2 * 9.81 m/s² * 0.42 m)
v ≈ 2.9 m/s
Using a kinematic equation to check our answer:
v² = v₀² + 2a(x - x₀)
v² = (0 m/s)² + 2(9.8 m/s²)(0.42 m)
v ≈ 2.9 m/s
True it’s true because in the book it said all that stuff
The sun’s energy is most useful to humans after it is converted to chemical energy. Living organisms like humans and animals could not directly utilize the energy from the sun because of lack in organs that would allow photosynthesis. Humans and animals obtain the energy from the sun from the intake of food. These foods contain chemical energy which is obtained from the solar energy of the sun. Plants use solar energy for photosynthesis which converts the energy into chemical energy. Then, animals and humans eat the plants obtaining the chemical energy which can readily processed by the body as compared to solar energy.
