Answer:
A. Heat flows from an object at higher temperature to an object at lower temperature
Explanation:
The option A obeys the 2nd law of thermodynamics. The heat will flow from the object at higher temperature to the object at Lower temperature till they reach an equilibrial state.
Heat doesn’t necessarily flow from an object with higher thermal energy to an object with lower thermal energy because an object has a higher thermal energy when it’s mass is more than the other. This makes B wrong.
C is wrong because heat moves from an object with higher temperature to objects with Lower temperature regardless of the state of matter.
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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Answer:

Explanation:
Work is equal to the product of force and distance.

The force is 8 Newtons and the distance is 15 meters.

Substitute the values into the formula.

Multiply.

- 1 Newton meter is equal to 1 Joule
- Our answer of 120 N*m equals 120 J

The work done is <u>120 Joules</u>
<span>4) Formation of a gas
When methane burns, it produces the gases water vapor and carbon dioxide.
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When you are on a huge water slide, the force present as you slide is the gravitational force. It is because the gravity enables you to slide down the water slide. The net force is the overall forces of the object, so as you slide the water slide, you may experience the net force once you slide down with the gravity and water sliding you down.