Answer:
False
Explanation:
We still use the old way. It's easier to understand the old way, and its NOT outdated.
Answer: c) Positive acceleration describes an increase in speed; negative acceleration describes a decrease in speed.
Hey
On Earth, you can move or you can not move. if you are moving 50 mph that means relative to Earth (not the Andromeda galaxy). When you start moving (accelerating) you are now moving relative to Earth. when you start slowing down (decelerating [most scientists just say you have negative acceleration]) you are starting to match your velocity to Earth's velocity.
Hope it helped and made any sence at all.
Spiky bob your answerer.
Answer:
electric motors is the answer
Answer:
<em>Correct choice: b 4H</em>
Explanation:
<u>Conservation of the mechanical energy</u>
The mechanical energy is the sum of the gravitational potential energy GPE (U) and the kinetic energy KE (K):
E = U + K
The GPE is calculated as:
U = mgh
And the kinetic energy is:

Where:
m = mass of the object
g = gravitational acceleration
h = height of the object
v = speed at which the object moves
When the snowball is dropped from a height H, it has zero speed and therefore zero kinetic energy, thus the mechanical energy is:

When the snowball reaches the ground, the height is zero and the GPE is also zero, thus the mechanical energy is:

Since the energy is conserved, U1=U2
![\displaystyle mgH=\frac{1}{2}mv^2 \qquad\qquad [1]](https://tex.z-dn.net/?f=%5Cdisplaystyle%20mgH%3D%5Cfrac%7B1%7D%7B2%7Dmv%5E2%20%20%20%20%5Cqquad%5Cqquad%20%5B1%5D)
For the speed to be double, we need to drop the snowball from a height H', and:

Operating:
![\displaystyle mgH'=4\frac{1}{2}m(v)^2 \qquad\qquad [2]](https://tex.z-dn.net/?f=%5Cdisplaystyle%20mgH%27%3D4%5Cfrac%7B1%7D%7B2%7Dm%28v%29%5E2%20%5Cqquad%5Cqquad%20%5B2%5D)
Dividing [2] by [1]

Simplifying:

Thus:
H' = 4H
Correct choice: b 4H
- The wavelength of the red light in "nanometer" is 7×

- Wavelength is given as : 7×
meter
- 1 nanometer = (
meter)
- Let X= value of the wavelength in nanometer.
1 nanometer =
meter
X nanometer = 7×
meter
- <em>If we Cross multiply</em>
X nanometer = (
)
X= 7×
nanometer
Therefore, the wavelength in "nanometer" is 7×
Learn more at :brainly.com/question/12924624?referrer=searchResults