Answer:
The theory of relativity usually encompasses two interrelated theories by Albert Einstein: special relativity and general relativity, proposed and published in 1905 and 1915, respectively. Special relativity applies to all physical phenomena in the absence of gravity. General relativity explains the law of gravitation and its relation to other forces of nature.It applies to the cosmological and astrophysical realm, including astronomy.
The theory transformed theoretical physics and astronomy during the 20th century, superseding a 200-year-old theory of mechanics created primarily by Isaac Newton. It introduced concepts including spacetime as a unified entity of space and time, relativity of simultaneity, kinematic and gravitational time dilation, and length contraction. In the field of physics, relativity improved the science of elementary particles and their fundamental interactions, along with ushering in the nuclear age. With relativity, cosmology and astrophysics predicted extraordinary astronomical phenomena such as neutron stars, black holes, and gravitational waves
Explanation:
PE= mgh
6 J= (3m) (9.81 m/s2) (mass)
mass=( 6)/(3×9.81)
mass= 0.20 Kg
Answer: False
A waterway refers to a water body that can be used for the transportation by human population. These includes rives, oceans, lakes, estuary and canals. A waterway should be wide and deep enough to allow the movement of water transportation vehicles like boats and ships. Water transportation is responsible for contaminating the water of waterways. As, the water transportation vehicles releases residues of fuel in the water, which deteriorate the quality of water and makes it unfit for survival of aquatic animal and plant species.
Hence, excess to waterways should be reduced in order to prevent water pollution. Reducing access to waterways will lead to decrease in human impact on waterways.
Therefore, the statement reducing access to waterways will lead to an increase in human impact on waterways is false.
Answer:
because of carbon content in wood harms environment , although forest can be replenished but no one wanted to plant a tree in his/ her home. And also, cutting of woods causes environmental imbalances. Further, burning of wood causes a lot of pollution. Hence, it is advisable not to use wood as a fuel.
Explanation:
Answer:
a)
<u>get mass of planet:</u>
ρ = M / V
V = 4/3 * R_1^3
M = ρ * V
M = ρ * 4/3 * R_1^3
<u>equate force equations:</u>
F = (GMm) / r^2 // r = R_2
F = ma
a = v^2/R_2
F = m * (v^2/R_2)
m * (v^2/R_2) = (GMm) / R_2^2
<u>plug in and solve v^2:</u>
m * (v^2/R_2) = (G * (ρ * 4/3 * R_1^3) *m) / R_2^2
v^2 = (G * ρ * (4/3) * π * R_1^3) / R_2
<u>put into kinetic energy equation:</u>
K = 1/2 * m * v^2
K = 1/2 * m * (G * ρ * (4/3) * π * R_1^3) / R_2
B)
<u>givens:</u>
U = -(GmM) / R_2
<u>plug in mass of planet:</u>
U = -(G * m * ρ * 4/3 * R_1^3) / R_2
C)
<u>use previous equations and do some algebra:</u>
K/U = (1/2 * m * (G * ρ * (4/3) * π * R_1^3) / R_2) * -(R_2 / (G * m * ρ * 4/3 * R_1^3))
K/U = -1/2