Answer:
Distance between centre of Earth and centre of Moon is 3.85 x 10⁸ m
Explanation:
The attractive force experienced by two mass objects is known as Gravitational force.
The gravitational force is determine by the relation:
....(1)
According to the problem,
Mass of Moon, m₁ = 7.35 x 10²² kg
Mass of Earth, m₂ = 5.97 x 10²⁴ kg
Gravitational force experienced by them, F = 1.98 x 10²⁰ N
Universal gravitational constant, G = 6.67 x 10⁻¹¹ Nm²kg⁻²
Substitute these values in equation (1).



d = 3.85 x 10⁸ m
Answer: Black hole.
Explanation:
As the massive star "compacts" under its own gravity, it triggers a massive supernova, after this point the remains of the star can become a neutron star, which is a very compact star made primarily, as the name says, of neutrons. The other possibility is a black hole, which is a finite region of space wherein it's interior there is a big concentration of mass, which creates a gravitational field strong enough that there is no particle that can escape it.
Answer:
The average speed for the entire run is 12 km/h.
Explanation:
The average speed is given by the following equation:

Where:
: is the total distance
: is the total time
If during the first hour, they ran a total of 13 kilometers and then, they ran 5.0 kilometers during the next half an hour we have:


Hence, the average speed is:

Therefore, the average speed for the entire run is 12 km/h.
I hope it helps you!
Answer:
T = 74°C
Explanation:
Given Mw = mass of water = 330g, Ma = mass of aluminium = 840g
Cw = 4.2gJ/g°C = specific heat capacity of water and Ca = 0.9J/g°C = specific heat capacity of aluminium
Initial temperature of water = 100°C.
Initial temperature of aluminium = 29°C
When the boiling water is poured into the aluminum pan, heat is exchanged and after a short time the water and aluminum pan both come to thermal equilibrium at a common temperature T.
Heat lost by water equal to the heat gained by aluminium pan.
Mw × Cw×(100 –T) = Ma × Ca × (T–29)
330×4.2×(100– T) = 890×0.9×(T–29)
1386(100 – T) = 801(T –29)
1386/801(100 – T) = T – 29
1.73(100 – T) = T – 29
173 –1.73T = T –29
173+29 = T + 1.73T
202 = 2.73T
T = 202/2.73
T = 74°C