This next statement is a big deal. It should be up on a board, surrounded
by flashing red and yellow lights, and hung on the wall of every Science
classroom. Although we never see it in our daily lives, it's fundamental to
the workings of the universe, and it's also Newton's first law of motion:
<em>Without friction, it doesn't take <u>ANY</u> force to keep a moving object
moving. </em><em>Force is only required to <u>change</u> the object's speed, or to
<u>change</u> the direction </em><em>in which it's moving.</em>
The answer to the question is: On a level road, and neglecting any friction,
the engine doesn't have to supply ANY force to keep the car going at the
same speed.
A 300-kg bear grasping a vertical tree slides down at constant velocity. The friction force between the
tree and the bear is
Answer:
11.23%
Explanation:
Lets take
Speed of man in still water =u= 1.73 m/s
Speed of flow of water = v=0.52 m/s
When swims in downward direction then speed of man = u + v
When swims in upward direction then speed of man = u - v
Lets time taken by man when he swims in downward direction is 
and when he swims in downward direction is 
Lets distance is d and it will be remain constant in both the case
Time taken in still water
2 d= t x 1.73
t=1.15 x d sec
total time in current = 0.82 +0.44 d=1.26 d sec
So the percentage time
Percentage time =11.32%
So it will take 11.32% more time as compare to still current.
Answer:
1. You push on the ball and the ball pushes on your hand
.
2. The ball hits the ground and the ground pushes back on the ball
.
3. You walk on the ground with your feet and the ground pushes back on you.
Explanation:
