D. they are composed of two or more types of matter
The same force accelerates a small mass faster than
it accelerates a large mass.
It's easier to get a little red wagon going by pushing it
than it is to get a school bus going by pushing it.
Which force is always perpendicular (90 degree angle) to a surface. So, if you are sitting on the floor, what is the name of the force "the floor pushes up on you"?
Question 4 options:
normal
Answer:
more than all the sand on all the beaches on Earth
a). is true. <span>All motion is relative to a frame of reference. That's a fancy
way of saying that whenever you talk about a distance, an acceleration,
or a speed, they're always compared to something. Many surprising
things come out of this:
-- There's no such thing as "how fast is it <u>really</u> moving".
-- There's no such thing as "how high is it <u>really</u>".
-- There's no such thing as "<u>really</u> moving" or "<u>really</u> at rest".
What about quantities where you use distance or motion to calculate them ?
Like . . . . .
Potential energy . . . . . (mass) x (gravity) x (<u>height</u>)
Kinetic energy . . . . . (1/2) (mass) (<u>speed</u>)²
Momentum . . . . . (mass) x (<u>speed</u>) .
Yep, that's right. Those things are all relative to a frame of reference too;
different observers can get different answers,and they're all correct ... for
their own frame of reference.
Simple example:
You're flying in a passenger jet to visit your grandma.
In the frame of reference of somebody on the ground, you're moving at
400 miles per hour.
In the frame of reference of the pilot or the person sitting next to you,
you are at rest, and you can listen to your pod or read a book ... (or
maybe you're <em>heavily</em> at rest and taking a nap :-).)
</span>