having to push a rough and heavy box across the floor to move it
Explanation:
Friction is not a useful force because we have to exert even more force to push a body that is rough and heavy across the floor to move it.
- Frictional force is a force that opposes the motion of a body.
- It costs more and uses more energy to push a rough and heavy box on surface because of friction.
- This wastes energy in systems that deals with pushing.
Friction is useful in that:
- the heat energy produced when two surfaces rub together is very useful.
- the friction between your feet and the floor keeping you from slipping and makes walking possible.
- the tread on tires helping the moving vehicle slow down and stop when necessary.
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Friction brainly.com/question/7174363
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A.
The planet contains matter and energy so it is a system.
Answer:
770.1 m
Explanation:
From the question given above, the following data were obtained:
Velocity (v) = 45.3 m/s
Time (t) = 17 s
Displacement (d) =?
Velocity is defined according to the following formula:
Velocity = Displacement /Time
With the above formula, we can obtain the displacement of the ball as follow:
Velocity = Displacement /Time
45.3 = Displacement / 17
Cross multiply
Displacement = 45.3 × 17
Displacement = 770.1 m
Therefore the displacement of the ball is 770.1 m
