na drewnianej podłodze znajduje się skrzynka o masie 18 kg . W pewnym momencie pod wpływem siły skierowanej poziomo skrzynia zac
1 answer:
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(a) north
We can treat the aircraft as a single point charge moving in a magnetic field. In this case, the magnetic force exerted on the plane is
where
is the charge on the plane
v = 660 m/s is the velocity
is the magnitude of the magnetic field
is the angle between the direction of motion of the jet and of the magnetic field
Substituting,
The direction can be found by using Fleming's left hand rule. We have:
- index finger: magnetic field direction (straight up)
- middle finger: velocity of the plane (due west)
- force: thumb --> north
(b) Not negligible
As we can see from part (a), the magnitude of the force is not really big, so the effects are negligible.
For instance, we can compare this force with the weight of a plane. If we take a Boeing 737, its mass is about 80,000 kg, so its weight is
As we can see, this is several orders of magnitude bigger than the magnetic force calculated at point (a), so the effects of the magnetic force are negligible.
Answer:
-40 kJ
80 kJ
Explanation:
Work is equal to the area under the pressure vs volume graph.
W = ∫ᵥ₁ᵛ² P dV
2.27) Pressure and volume are linearly related. When we graph P vs V, the area under the line is a trapezoid. So the work is:
W = ½ (P₁ + P₂) (V₂ − V₁)
W = ½ (100 kPa + 300 kPa) (0.1 m³ − 0.3 m³)
W = -40 kJ
2.29) Pressure and volume are inversely proportional:
pV = k
The initial pressure and volume are 500 kPa and 0.1 m³. So the constant is:
(500) (0.1) = k
k = 50
The final pressure is 100 kPa. So the final volume is:
(100) V = 50
V = 0.5
The work is therefore:
W = ∫ᵥ₁ᵛ² P dV
W = ∫₀₁⁰⁵ (50/V) dV
W = 50 ln(V) |₀₁⁰⁵
W = 50 (ln 0.5 − ln 0.1)
W ≈ 80 kJ
