Answer:
2.69 m/s
Explanation:
Hi!
First lets find the position of the train as a function of time as seen by the passenger when he arrives to the train station. For this state, the train is at a position x0 given by:
x0 = (1/2)(0.42m/s^2)*(6.4s)^2 = 8.6016 m
So, the position as a function of time is:
xT(t)=(1/2)(0.42m/s^2)t^2 + x0 = (1/2)(0.42m/s^2)t^2 + 8.6016 m
Now, if the passanger is moving at a constant velocity of V, his position as a fucntion of time is given by:
xP(t)=V*t
In order for the passenger to catch the train
xP(t)=xT(t)
(1/2)(0.42m/s^2)t^2 + 8.6016 m = V*t
To solve this equation for t we make use of the quadratic formula, which has real solutions whenever its determinat is grater than zero:
0≤ b^2-4*a*c = V^2 - 4 * ((1/2)(0.42m/s^2)) * 8.6016 m =V^2 - 7.22534(m/s)^2
This equation give us the minimum velocity the passenger must have in order to catch the train:
V^2 - 7.22534(m/s)^2 = 0
V^2 = 7.22534(m/s)^2
V = 2.6879 m/s
Answer:
Energy conversion in flashlight.
Explanation:
When the switch of a flashlight is on, then the batteries inside them will be connected in a circuit and chemical energy from the batteries will be converted into electrical energy and then the electrical energy will be converted into light energy.
Light energy is also called electromagnetic energy.
Hence, among the given options the correct one is the first option that is:
1. Electrical energy into electromagnetic energy is the answer.
Answer:
a. 2143 turns/m
b. 111.5 m
Explanation:
a. The minimum number of turns per unit length (N/L) can be found using the following equation:


Hence, the minimum number of turns per unit length is 2143 turns/m.
b. The total length of wire is the following:

Since each turn has length 2πr of wire, the total length is:

Therefore, the total length of wire required is 111.5 m.
I hope it helps you!
Answer:
c. The temperature at which a glass transforms from a solid to liquid.
Explanation:
The glass transition temperature is said to be a temperature range when a polymer structure transition from a glass or hardy(solid) material to a rubber like or viscous liquid material.
The glass transition temperature is an important property that is critical in product design.