Answer:
196J
Explanation:
Given parameters:
Mass of skateboard = 1kg
Height off the ground = 20m
Unknown:
Potential energy = ?
Solution:
The potential energy is the energy due to the position of a body above the ground.
It is mathematically expressed as:
Potential energy = mass x acceleration due gravity x height
Potential energy = 1 x 9.8 x 20 = 196J
The distance between city a and city b is 833.345 miles.
We know that
1°=60'
The distance of city a from the initial ray is calculated as
x_a=3960*tan45.46°=4024.101 miles
The distance of city b from the initial ray is calculated as
x_b=3960*tan 38.86°=3190.75 miles
Now the distance between city a and b is equal to
4024.101-3190.75=833.345 miles
This is the vertical distance between the cities.
Answer: They behave the same because, according to the principle of equivalence, the laws of physics work the same in all frames of reference.
Explanation:
According to the equivalence principle postulated by Einstein's Theory of General Relativity, acceleration in space and gravity on Earth have the same effects on objects.
To understand it better, regarding to the equivalence principle, Einstein formulated the following:
A gravitational force and an acceleration in the opposite direction are equivalent, both have indistinguishable effects. Because the laws of physics must be accomplished in all frames of reference.
Hence, according to general relativity, gravitational force and acceleration in the opposite direction (an object in free fall, for example) have the same effect. This makes sense if we deal with gravity not as a mysterious atractive force but as a geometric effect of matter on spacetime that causes its deformation.