Ok so the unit of density is kg/m^3
The basic unit involved are kg which is weight of the body and m^3 which is the area of the body
Answer: 80N (choice #4)
Explanation: The force of gravity is proportional to the inverse of the square of the distance. That means, if the distance is cut in half, the square of that is 1/4, and the inverse of that is a factor 4. So the force increases by a factor of 4. Given that the force is 20N, the new force will be 4*20N=80N.
Answer:
a) t = 2 10⁻² s
, t = 2.4 10-1 s
Explanation:
In this exercise they indicate the delay in two signals
a) A signal travels on an electrical cable, between New York and London.
The wave formed in this wire for the signal. This wave travels at the speed of light, c = 3 108 m / s, so the delay is very small
t = d / c
t = 6000 10³/3 10⁸
t = 2 10⁻² s
b) The signal points to a satellite in geostationary orbit
distance traveled = √ (2 36000 10³)² + 6000²
distance = 72 10⁶ m
the waiting time is
t = d / c
t = 72 10⁶/3 10⁸
t = 2.4 10-1 s
we can see that the signal sent by the satellites has more delay because its distance is much greater
