Remember Dark Energy is repulsive, the more the faster the universe expands (indeed accelerates), so the faster it would cool down and increase its size, not the other way. Now, no one knows what it is. For instance, if Dark Energy would rather be some other geometric effect, it could have a different ending than just if it is a cosmological constant term. So far, though, all experimental data do not favor anything else that is not compatible with just a cosmological constant ... We'll need to wait few years (~10 years) to get to know much better this with missions and ground experiments that are undergoing or planned to be launched.
Answer:
5 hours
Explanation:
Let the required time be x hours. The time will be the same for both cars.
The cars will cover different distances because they are travelling at different speeds.
<em>D=S×T
</em>
The distance travelled by the slower car = 50×x miles.
The distance travelled by the faster car = 58×x miles.
The two distances differ by 40 miles.
58x−50x=40
8x=40
x=5 hours
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A second method:
The difference in the distances is 40 miles
The difference in the speeds is #8mph.
The time to make up the 40 miles=
=5 hours
Answer:
The driver was not telling the truth because it is not possible for a car to hit another car from behind and generate a force to the sides that deflects it from its path.
Explanation:
First, we analyze the driver's statement.
The driver when arriving at the curve, is collided from behind by another car and deviates from his path and crashes into a tree. For the car to go to the tree there must be a force towards the tree.
The net force that causes the car to deviate must be formed by the sum of the motion vector of the first car plus the force that is directed towards the tree.
Here we verify that a car hitting from behind will not generate a force to the sides, but will generate a force in the same direction that the car moves, forward.
Answer:
The coefficient of kinetic friction between the sled and the snow is 0.0134
Explanation:
Given that:
M = mass of person = 52 kg
m = mass of sled = 15.2 kg
U = initial velocity of person = 3.63 m/s
u = initial velocity of sled = 0 m/s
After collision, the person and the sled would move with the same velocity V.
a) According to law of momentum conservation:
Total momentum before collision = Total momentum after collision
MU + mu = (M + m)V

Substituting values:

The velocity of the sled and person as they move away is 2.81 m/s
b) acceleration due to gravity (g) = 9.8 m/s²
d = 30 m
Using the formula:

The coefficient of kinetic friction between the sled and the snow is 0.0134