Answer:
d=510.2m
t=10.2s
Explanation:
The formulas for accelerated motion are:

From them we can get
.
We have:

And substitute:

We multiply both sides by 2a, and continue:

Being d the displacement
, we have 
For our exercise, we will write this as:

And taking upwards direction positive and imposing final velocity 0m/s (for maximum height), we have:

For the time we use:

Answer:
<h2>
16,931 turns</h2>
Explanation:
The magnetic field produced is expressed using the formula

B is the magnetic field = 0.30T
I is the current produced in the coil = 4.5A
is the magnetic permittivity in vacuum = 1.26*10^-6Tm/A
L is the length of the solenoid = 32 cm = 0.32 m
N is the number of turns in the solenoid.
Making N the subject of the formula from the equation above;


Substituting the give values to get N;

The number of turns the solenoid must have is approximately 16,931 turns
If you are talking about sound frequency you need to consider what area you are in because in a concert hall it is big and helps the sound spread but in an airplane it is the opposite.
Answer:
D) a Battery
Explanation:
The best real-life example of direct current is a battery. Batteries have positive and negative terminals on a battery, the electrons in the wires will begin to flow to produce a current.
The letter "B" is used for magnetic field