Answer:
168 seconds (2 min 48 s)
Explanation:
Find the heat absorbed by the water.
q = mCΔT
q = (1 kg) (4200 J/kg/K) (70°C − 40°C)
q = 126,000 J
Power is energy per time.
P = q / t
750 W = 126,000 J / t
t = 168 s
It takes 168 seconds (2 min 48 s).
Answer:
v = √ 2 G M/
Explanation:
To find the escape velocity we can use the concept of mechanical energy, where the initial point is the surface of the earth and the end point is at the maximum distance from the projectile to the Earth.
Initial
Em₀ = K + U₀
Final
=
The kinetic energy is k = ½ m v²
The gravitational potential energy is U = - G m M / r
r is the distance measured from the center of the Earth
How energy is conserved
Em₀ =
½ mv² - GmM / = -GmM / r
v² = 2 G M (1 / – 1 / r)
v = √ 2GM (1 / – 1 / r)
The escape velocity is that necessary to take the rocket to an infinite distance (r = ∞), whereby 1 /∞ = 0
v = √ 2GM /
You need to know the time as well.
Answer:
M = 328.70g
Explanation:
From the given values:
V = 346 cm³
M of 1 cm³ of Polythene = 0.95g or 95/100g
Solve:
M = <u>(95×346)</u>
10
= <u>3</u><u>2</u><u>8</u><u>7</u><u>0</u>
100
M = 328.70g
Answer:
a) 5.63 atm
Explanation:
We can use combined gas law
<em>The combined gas law</em> combines the three gas laws:
- Boyle's Law, (P₁V₁ =P₂V₂)
- Charles' Law (V₁/T₁ =V₂/T₂)
- Gay-Lussac's Law. (P₁/T₁ =P₂/T₂)
It states that the ratio of the product of pressure and volume and the absolute temperature of a gas is equal to a constant.
P₁V₁/T₁ =P₂V₂/T₂
where P = Pressure, T = Absolute temperature, V = Volume occupied
The volume of the system remains constant,
So, P₁/T₁ =P₂/T₂
a)