Answer:
The idea behind space expansion is that after the big bang, the universe started infinitely expanding. It's also called metric expansion. Stephen Hawking's A Brief History of Time goes further into detail on this.
Answer:
It requires more tension to pull up the track
Explanation:
Net force must be zero to maintain constant velocity.
Weight force will always be pointed down the slope. Call it W
Friction force (Call it Ff) will be down slope when movement is up slope.
Friction force will be up slope when movement is down slope.
W and Ff are always positive numbers
Call the pulling force T
If Up slope is considered the positive direction
Moving up slope
Tu - Ff - W = 0
Tu = Ff + W
Moving down slope
Td + W - Ff = 0
Td = Ff - W
Ff + W > Ff - W therefore Tu > Td
Your bedroom has a rectangular shape, and you want to measure its area. You use a tape that is precise to 0.001 and find that the shortest wall in the room is 3.547 long. The tape, however, is too short to measure the length of the second wall, so you use a second tape, which is longer but only precise to 0.01 . You measure the second wall to be 4.79 long. Which of the following numbers is the most precise estimate that you can obtain from your measurements for the area of your bedroom?
b)If your bedroom has a circular shape, and its diameter measured 6.32 , which of the following numbers would be the most precise value for its area?
a)30 m^2
b) 31.4 m^2
c)31.37 m^2
d)31.371 m^2
Answer:
Part A

Part B

Explanation:
From the question we are told that
The shortest wall is 
The length of the second wall is 
Generally the area is mathematically evaluated as

=> 
=> 
Given that the diameter is d = 6.32
Then the area is


