To solve this problem it is necessary to apply the concepts related to Faraday's law and the induced emf.
By definition the induced electromotive force is defined as


Where,
Electric field
B = Magnetic Field
A = Area
At the theory the magnetic field is defined as,

Where,
N = Number of loops
I = current
Permeability constant
We know also that the cross sectional area, is the area from a circle, and the length is equal to the perimeter then
A = \pi r^2
l = 2\pi r
Replacing at the previous equation we have that

Where,
R = Radius of the solenoid
r = The distance from the axis
Re-arrange to find the current in function of time,

Replacing our values we have


In electrical circuit, this arrangement is called a R-L series circuit. It is a circuit containing elements of an inductor (L) and a resistor (R). Inductance is expressed in units of Henry while resistance is expressed in units of ohms. The relationship between these values is called the impedance, denoted as Z. Its equation is
Z = √(R^2 + L^2)
Z = √((1.24×10^3 ohms)^2 + (6.95×10^-6 H)^2)
Z = 1,240 ohms
The unit for impedance is also ohms. Since the circuit is in series, the voltage across the inductor and the resistor are additive which is equal to 12 V. Knowing the impedance and the voltage, we can determine the maximum current.
I = V/Z=12/1,240 = 9.68 mA
But since we only want to reach 73.6% of its value, I = 9.68*0.736 = 7.12 mA. Then, the equation for R-L circuits is

, where τ = L/R = 6.95×10^-6/1.24×10^3 = 5.6 x 10^-9
Then,
t = 7.45 nanosecondsPart B.) If t = 1.00τ, then t/τ = 1. Therefore,
I = 6.12 mA
Answer:No
Explanation:
No
As the train is accelerating so train velocity will be more as compared to the ball and thus will cover more distance as compared to the ball.
When the ball is thrown upward with some velocity, it also possesses the train velocity at the time of throwing but as time passes velocity of train increases due to acceleration of the train. This causes the ball to fall behind the point of launch.
Answer:
The speed of the combined vehicles is 6.82m/s
Explanation:
Using the law of conservation of momentum which stayed that the sum of momentum of bodies before collision is equal to their sum of momentum after collision. After collision, both object moves with the same velocity.
Momentum = mass×velocity
Before collision:
Momentum of vehicle or mass 3000kg moving with velocity 25m/s
= 3000×25
= 75000kgm/s
Pa = 75000kgm/s
Momentum of vehicle with mass 2500kg moving with velocity of -15m/s
= 2500×-15
= -37500kgm/s
After collision:
Momentum = (3000+2500)V
Where v is their common velocity
Momentum after collision = 5500V
Based on the law:
75000+(-37500) = 5500V
75000-37500 = 5500V
37500 = 5500V
V = 37500/5500
V = 6.82m/s
We can use the equation of state for an ideal gas to answer the question:

or, by rewriting it,

where p is the gas pressure, V its volume, T its temperature, n the number of moles of the gas and R the gas constant.
When the gas is sprayed from the can into the room, its volume V has increased, while n (the number of moles of the gas) stayed the same. Since R is a constant and the temperature T also stayed constant, if we look at the formula we see that the numerator didn't change, while the denominator (V) has increased, so the pressure of the gas has decreased.