Answer:
The surface gravity g of the planet is 1/4 of the surface gravity on earth.
Explanation:
Surface gravity is given by the following formula:
So the gravity of both the earth and the planet is written in terms of their own radius, so we get:
The problem tells us the radius of the planet is twice that of the radius on earth, so:
If we substituted that into the gravity of the planet equation we would end up with the following formula:
Which yields:
So we can now compare the two gravities:
When simplifying the ratio we end up with:
So the gravity acceleration on the surface of the planet is 1/4 of that on the surface of Earth.
Answer:
The average induced emf around the border of the circular region is 
.
Explanation:
Given that,
Radius of circular region, r = 1.5 mm
Initial magnetic field, B = 0
Final magnetic field, B' = 1.5 T
The magnetic field is pointing upward when viewed from above, perpendicular to the circular plane in a time of 125 ms. We need to find the average induced emf around the border of the circular region. It is given by the rate of change of magnetic flux as :
So, the average induced emf around the border of the circular region is .
The answer is the second option, or 1/10 the same momentum.
Explanation:
When a man falls on a hard cemented floor his momentum reduced to zero in a very short time and hurt the man. Whereas when a man falls on a heap of sand. As sand can compress, it takes longer time for the man to hit the ground (or hard surface)
Answer:
Explanation:
Force between two charges is given by the following expression
F = 
Q₁ and Q₂ are two charges and d is distance between two.
.1 =
If Q₁ becomes three times , force will become 3 times . Hence force becomes .3 N in the first case.
Force F = .3 N
If charge becomes one fourth , force also becomes one fourth .
F= 
= .025 N.
