When an object like a tree is illuminated by the sun, and you are looking toward the tree, light rays leave the object _________
1 answer:
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Answer:
V1 =8.1 m/s
Explanation:
height at highest point (h2) = 4.1 m
height at lowest point (h1) = 0.8 m
acceleration due to gravity (g) = 9.8 m/s^{2}
from conservation of energy, the total energy at the lowest point will be the same as the total energy at the highest point. therefore
mgh1 + = mgh2 +
where
- speed at highest point = V2
- speed at lowest point = V1
- mass of the girl and swing = m
- at the highest point, the speed is minimum (V1 = 0)
- at the lowest point the speed is maximum (V2 is the maximum speed)
- therefore the equation becomes mgh1 +
= mgh2
m(gh1 + ) = m(gh2)
gh1 + = gh2
V1 =
now we can substitute all required values into the equation above.
V1 =
V1 =
V1 =8.1 m/s
Answer:
The distance travelled does not depend on the mass of the vehicle. Therefore,
Explanation:
This deceleration situation can be analyzed by means of Work-Energy Theorem, where change in translational kinetic energy is equal to the work done by friction:
(1)
Where:
- Mass of the car, in kilogram.
- Initial velocity, in meters per second.
- Coefficient of friction, no unit.
- Travelled distance, in meters.
Then we derive an expression for the distance travelled by the vehicle:
As we notice, the distance travelled does not depend on the mass of the vehicle. Therefore,