When the tractor pulls, the boy moves. When the elephant moves, the boy moves. If the elephant moves and has more power than the tractor, the tractor and the boy moves. If the tractor moves and has more power than the elephant, then the elephant and the boy moves. I hope this helps you, have a great day!
First you need to make a difference between friction while object is stationary and the friction while object is moving. Force required to start moving some object is slightly greater than force required to maintain objects movement. That means that to move a chair you need some force F1 but you can than slightly reduce force and chair will still be moving.
Now to the problem in this question: It can be said that "stationary friction force" is equal to 15 Newtons. Its also good to know that friction force between chair and floor while you are increasing your push is also increasing and is equal to force of your push. Once it reaches 15N which is it "critical value" for that chair, chair starts moving and friction force drops a little bit and now it is called friction force of moving chair.
Answer:
m
Explanation:
At 10am, the minute hand and hour hand are ' 2 hours apart', since the minute hand is at 12pm and hour hand is at 10am.
Angle between the two hands = 2/12 * 360
= 60°
Arc Length = 
= 
The answer is has no moons. Mars has two moons