Answer:
125÷2= 62.5 is your average speed. If the train was resting it's not moving your going nowhere . If the train is traveling at constant speed in a straight line it's speed will increase going through mountains will slow it down. if the train is coming to a braking force its speed will decrease
Answer:

or

Explanation:
As we know that the beat frequency is given as

here we know that


now we have

now we have

so we have

or

Answer:

Explanation:
first ball rolls on the porch by total distance

Then again it will move on horizontal floor

also in vertical direction it will drop down

so we have



so magnitude of net displacement of the ball is given as


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