C. A cation as a cation is positively charged and when an atom loses an electron it forms a positive ion.
The work done on the car is -20 J.
Work done on the car is negative, meaning that the car actually does work on the external system.
<h3>Energy and law of conservation of energy</h3>
- Energy is the ability to do work
- the law of conservation of energy states that the total energy in a system is conserved
From the law of conservation of energy, the initial energy of the car before it moves down the road remains constant or unchanged.
- Initial energy = 100 J
- Initial energy = Final energy - work done on car
- Final Energy = Work done on car + initial energy
80J = Work done on car + 100 J
Work done on car = 80 - 100J
Work done on car = -20 J
Hence, the work done on the car is -20 J
Work done on car is negative.
Since work done on the car is negative, it means that the car actually does work on the external system. Hence, the decrease in the energy of the car.
Learn more about energy and work at: brainly.com/question/13387946
A. The acceleration during the slide is 6.86 m/s²
B. The time taken to slide until he stops is 1.2 s
<h3>How to determine the force of friction</h3>
- Mass (m) = 81.5 Kg
- Coefficient of friction (μ) = 0.7
- Acceleration due to gravity (g) = 9.8 m/s²
- Normal reaction (N) = mg = 81.5 × 9.8 = 798.7 N
- Frictional force (F) =?
F = μN
F = 0.7 × 798.7
F = 559.09 N
<h3>A. How to determine the acceleration</h3>
- Mass (m) = 81.5 Kg
- Frictional force (F) = 559.09 N
- Acceleration (a) =?
a = F / m
a = 559.09 / 81.5
a = 6.86 m/s²
<h3>B. How to determine the time </h3>
- Initial velocity (u) = 8.23 m/s
- Final velocity (v) = 0 m/s
- Decceleration (a) = -6.86 m/s²
- Time (t) =?
a = (v – u) / t
t = (v – u) / a
t = (0 – 8.23) / -6.86
t = 1.2 s
Learn more about acceleration:
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It is a surface force
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