Answer:

Explanation:
The apparent brightness follows an inverse square law, therefore we can write:

where I is the apparent brightness and r is the distance from the Sun.
We can also rewrite the law as
(1)
where in this problem, we have:
apparent brightness at a distance
, where
million km
We want to estimate the apparent brightness at
, where
is ten times
, so

Re-arranging eq.(1), we find
:

Answer:
Selenium dichloride
Explanation:
Selenium (Se) and Chlorine (Cl) are both elements capable of combining together to form a compound with the chemical formula; SeCl2. Since the chlorine atom is more electronegative than selenium atom, the chlorine pulls more electrons towards itself to form an IONIC bond.
The SeCl2 compound formed is called Selenium dichloride as two atoms of Chlorine are needed to combine with one atom of Selenium to form the compound.
Answer:
1500 mph
Explanation:
Take east to be +x and north to be +y.
The x component of the velocity is:
vₓ = 889 cos 0° + 830 cos 59°
vₓ = 1316.5 mph
The y component of the velocity is:
vᵧ = 889 sin 0° + 830 sin 59°
vᵧ = 711.4 mph
The speed is found with Pythagorean theorem:
v² = vₓ² + vᵧ²
v² = (1316.5 mph)² + (711.4 mph)²
v = 1496 mph
Rounded to two significant figures, the jet's speed relative to the ground is 1500 mph.
Answer:
The mass of object is calculated as 5.36 kg
Explanation:
The known terms to find the mass are:
acceleration of object (a) = 22.35 
Force exerted (F) = 120N
mass of an object (m) = ?
From Newton's second law of motion;
F = ma
or, 120 = m × 22.35
or, m=
kg
∴ m = 5.36 kg