Answer:
The correct answer is 0,2 rems
Explanation:
People are exposed to natural sources of radiation all the time. According to recent estimates, the average person in the United States receives an effective dose of approximately 3 mSv per year of natural radiation, which is equivalent to 0.3 rems. This amount includes cosmic radiation from outer space and is average because it varies depending on the region people are in.
The amount of radiation for a chest x-ray of an adult (0.01 rems) is approximately equal to 10 days of natural radiation to which we are all exposed every day.
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Answer: 1) a = 9.61m/s² pointing to west.
2) (a) Δv = - 37.9km/s
(b) a = - 6.10⁷km/years
Explanation: Aceleration is the change in velocity over change in time.
1) For the plane:
a = 9.61m/s²
The plane is moving east, so velocity points in that direction. However, it is stopping at the time of 13s, so acceleration's direction is in the opposite direction. Therefore, acceleration points towards west.
2) Total change of velocity:
km/s
The interval is in years, so transforming seconds in years:
v = 
km/years
Calculating acceleration:
Acceleration of an asteroid is a = -6.10⁷km/years .
The substance has changed, It dissolved, and it evaproted.
Answer:
The gravitational potential energy of a system is -3/2 (GmE)(m)/RE
Explanation:
Given
mE = Mass of Earth
RE = Radius of Earth
G = Gravitational Constant
Let p = The mass density of the earth is
p = M/(4/3πRE³)
p = 3M/4πRE³
Taking for instance,a very thin spherical shell in the earth;
Let r = radius
dr = thickness
Its volume is given by;
dV = 4πr²dr
Since mass = density* volume;
It's mass would be
dm = p * 4πr²dr
The gravitational potential at the center due would equal;
dV = -Gdm/r
Substitute (p * 4πr²dr) for dm
dV = -G(p * 4πr²dr)/r
dV = -G(p * 4πrdr)
The gravitational potential at the center of the earth would equal;
V = ∫dV
V = ∫ -G(p * 4πrdr) {RE,0}
V = -4πGp∫rdr {RE,0}
V = -4πGp (r²/2) {RE,0}
V = -4πGp{RE²/2)
V = -4Gπ * 3M/4πRE³ * RE²/2
V = -3/2 GmE/RE
The gravitational potential energy of the system of the earth and the brick at the center equals
U = Vm
U = -3/2 GmE/RE * m
U = -3/2 (GmE)(m)/RE
The teeth and threads creates roughness that increases the friction between the tire and the road.
