Answer:
R = 5.28 103 km
Explanation:
The definition of density is
ρ = m / V
V = m /ρ
Where m is the mass and V the volume of the body
The volume of a sphere is
V = 4/3 π r³
Let's replace
4/3 π r³ = m / ρ
R =∛ ¾ m / ρ π
The mass of the planet is
M = 5.5 Me
R = ∛ ¾ 5.5 Me /ρ π
Let's reduce the density to SI units
ρ = 1.76 g / cm³ (1 kg / 10³ g) (10² cm / 1 m)³
ρ = 1.76 10³ kg / m³
Let's calculate
R = ∛ ¾ 5.5 5.97 10²⁴ / (1.76 10³ pi)
R = ∛ 0.14723 10²¹
R = 0.528 10⁷ m
R = 0.528 104 km
R = 5.28 103 km
Answer:
The friction force is 250 N
Explanation:
The desk is moving at constant velocity. This means that its acceleration is zero: a = 0. Newton's second law states that the resultant of the forces acting on the desk is equal to the product between mass (m) and acceleration (a):

In this case, we know that the acceleration is zero: a = 0, so also the resultant of the forces must be zero:
(1)
We are only interested in the forces acting along the horizontal direction, since it is the direction of motion. There are two forces acting in this direction:
- the pull, forward, F = 250 N
- the friction force, backward, 
Given (1), we have

So the force of friction must be equal to the pull:

Answer: The volume of gas expands because of the decrease in pressure as he tries to exit the water body, therefore he must take necessary precaution.
Explanation:
Using Boyle's law which states that the the pressure of a given mass of an ideal gas is inversely proportional to its volume at a constant temperature
ie P1VI=P2V2
A diver absorbs compressed nitrogen gas when he dives into the water body, As he ascends out of the water body having less pressure, the volume of nitrogen gas which he absorbs will tend to expand following Boyle's Law. Therefore a scuba driver should not rises quickly but slowly to the surface or else the expanding nitrogen gas can cause tiny bubbles in his blood and tissue to form together with joints pains and eventually cause decompression sickness needing medical attention.
Answer:
The linear charge density is 5.19 X 10⁻⁶ C/m
Explanation:
The potential difference between two cylinders, is given as
V = (λ/2πε)ln(b/a)
where;
λ is the line charge density on the power line.
b is the distance between the power line = 1 m
a is the radius of the wire = 1.5 cm = 0.015 m
ε is the permittivity of free space = 8.9 X 10⁻¹² C
V*2πε = λ* ln(b/a)
3900 *(2π*8.9 x10⁻¹²)= λ *ln(1/0.015)
2.1812 X 10⁻⁷ = 4.1997* λ
λ = 5.19 X 10⁻⁶ C/m
Therefore, the linear charge density is 5.19 X 10⁻⁶ C/m