The bus is going forward and suddenly stops
Complete question:
A 45-mH ideal inductor is connected in series with a 60-Ω resistor through an ideal 15-V DC power supply and an open switch. If the switch is closed at time t = 0 s, what is the current 7.0 ms later?
Answer:
The current in the circuit 7 ms later is 0.2499 A
Explanation:
Given;
Ideal inductor, L = 45-mH
Resistor, R = 60-Ω
Ideal voltage supply, V = 15-V
Initial current at t = 0 seconds:
I₀ = V/R
I₀ = 15/60 = 0.25 A
Time constant, is given as:
T = L/R
T = (45 x 10⁻³) / (60)
T = 7.5 x 10⁻⁴ s
Change in current with respect to time, is given as;
Current in the circuit after 7 ms later:
t = 7 ms = 7 x 10⁻³ s
Therefore, the current in the circuit 7 ms later is 0.2499 A
Answer:
4.02 s
Explanation:
From the question given above, the following data were obtained:
Angle of projection (θ) = 35°
Initial velocity (u) = 50 m/s
Acceleration due to gravity (g) = 10 m/s²
Time of flight (T) =?
The time of flight of the arrow can be obtained as follow:
T = 2uSineθ / g
T = 2 × 35 × Sine 35 / 10
T = 70 × 0.5736 / 10
T = 7 × 0.5736
T = 4.02 s
Therefore, the time taken for the arrow to return is 4.02 s
Answer:
Option (b)
Explanation:
Maxwell right hand thumb rule: if we hold a current carrying conductor in our right hand such taht the thumb indicates the direction of current then the curling of fingers give the direction of magnetic field around the conductor and vice versa.
Here the current is counterclockwise so by use of Maxwell right hand thumb rule the direction of magnetic field is straight up.
Answer:
75 m/s is the right answer