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.
the number of neutrons may b 21
Answer is d using a heavier string
B, since it is the only one that actually conserves matter for certain. In each of the others, matter could still be imbalanced, since for A, for example, it could be 5 Carbons on the right and 5 Chlorines on the left, and that would not balance.
Explanation:
The de broglie wavelength is given by :

Here,
h is Planck's constant
p is momentum
Momentum and De-Broglie wavelength has inverse relationship. If momentum of an electron double, its wavelength gets half.