Answer:
d. at the same velocity
Explanation:
I will assume the car is also travelling westward because it was stated that the helicopter was moving above the car. In that case, it depends where the observer is. If the observer is in the car, the helicopter would look like it is standing still ( because both objects have the same velocity). If the observer is on the side of the road, both objects would be travelling at the same velocity. Also recall that, velocity is a vector quantity; it is direction-aware. Velocity is the rate at which the position changes but speed is the rate at which object covers distance and it is not direction wise. Hence velocity is the best option.
Motion map has the points spaced farther apart (because the car would go a
further distance in each second), and the velocity vectors (arrows) are longer, because the car is
moving faster. So 'with longer vectors' is the correct answer
Answer:
Note: Angular momentum is always conserved in a collision.
The initial angular momentum of the system is
L = ( It ) ( ωi )
where It = moment of inertia of the rotating circular disc,
ωi = angular velocity of the rotating circular disc
The final angular momentum is
L = ( It + Ir ) ( ωf )
where ωf is the final angular velocity of the system.
Since the two angular momenta are equal, we see that
( It ) ( ωi ) = ( It + Ir ) ( ωf )
so making ωf the subject of the formula
ωf = [ ( It ) / ( It + Ir ) ] ωi
Explanation:
Refer to the figure below.
R = resistance.
Case 1:
The voltage source is V₁ and the current is 10 mA. Therefore
V₁ = (10 mA)R
Case 2:
The voltage source is V₂ and the current is 8 mA. Therefore
V₂ = (8 mA)R
Case 3:
The voltage across the resistance is V₁ - V₂. Therefore the current I is given by
V₁ - V₂ = IR
10R - 8R = (I mA)R
2 = I
The current is 2 mA.
Answer: 2 mA
Answer: 2.1 %
Explanation:
The radius of the Argon atom, r = 71 pm = 7.1 × 10 ⁻¹¹ m
Average orbital speed of electrons, v = 3.9 × 10⁷ m/s
From uncertainty principle:
Δx m Δv ≥ h/4π
mass of electron, m = 9.1 ×10⁻³¹ kg
Δx = radius of the argon atom = 7.1 × 10 ⁻¹¹ m


Percentage uncertainty:
