Impulse = (force) x (length of time the force lasts)
I see where you doodled (60)(40) over on the side, and you'll be delighted
to know that you're on the right track !
Here's the mind-blower, which I'll bet you never thought of:
On a force-time graph, impulse (also change in momentum)
is just the <em>area that's added under the graph during some time</em> !
From zero to 60, the impulse is just the area of that right triangle
under the graph. The base of the triangle is 60 seconds. The
height of the triangle is 40N . The area of the triangle is not
the whole (base x height), but only <em><u>1/2 </u></em>(base x height).
1/2 (base x height) = 1/2 (60s x 40N) = <u>1,200 newton-seconds</u>
<u>That's</u> the impulse during the first 60 seconds. It's also the change in
the car's momentum during the first 60 seconds.
Momentum = (mass) x (speed)
If the car wasn't moving at all when the graph began, then its momentum is 1,200 newton-sec after 60 seconds. Through the convenience of the SI system of units, 1,200 newton-sec is exactly the same thing as 1,200 kg-m/s . The car's mass is 3 kg, so after 60 sec, you can write
Momentum = M x V = (3 kg) x (speed) = 1,200 kg-m/s
and the car's speed falls right out of that.
From 60to 120 sec, the change in momentum is the added area of that
extra right triangle on top ... it's 60sec wide and only 20N high. Calculate
its area, that's the additional impulse in the 2nd minute, which is also the
increase in momentum, and that'll give you the change in speed.
The equal and opposite reaction to the gravitational force of the Earth pulling down on a man standing on the beach is the gravitational force of the man pulling up on the Earth. <em>(A)</em>
To put it in other words ... which should begin to blow your mind if you just take a moment to think about them ...
Your weight on Earth is exactly equal to the Earth's weight on YOU.
Frequency = 1/period. ... 1 / 18 sec = (1/18) per sec. That's 0.056 per sec or 0.056 Hz. (rounded)
(5.6 x 10^-2 Hz)
A reactant since it is on the left of the arrow
Full Question:
Why do we use other bonding theories in addition to the lewis model?
a) Lewis model is not suitable for all molecules or ions. b) Lewis model cannot predict all of the properties of a molecule or ion. c) Lewis model is too complicated.
Answer:
b) Lewis model cannot predict all of the properties of a molecule or ion.
Explanation:
Lewis structures, also called electron-dot structures or electron-dot diagrams, are diagrams that show the bonding between atoms of a molecule, and the lone pairs of electrons that may exist in the molecule.
Lweis model does not explain the geometry of molecules, how the bonds form, or how the electrons are shared between the atoms hence the need to use other bonding theories.
