Answer:
acceleration 8 km/h/s south
Explanation:
First of all, let's remind that a vector quantity is a quantity which has both a magnitude and a direction.
Based on this definition, we can already rule out the following two choices:
distance: 40 km
speed: 40 km/h
Since they only have magnitude, they are not vectors.
Then, the following option:
velocity: 5 km/h north
is wrong, because the car is moving south, not north.
So, the correct choice is
acceleration 8 km/h/s south
In fact, the acceleration can be calculated as
where
v = 40 km/h is the final velocity
u = 0 is the initial velocity
t = 5 s is the time
Substituting,
And since the sign is positive, the direction is the same as the velocity (south).
Answer: Use the Right -hand Rule to find the direction of the magnetic field.
Explanation: A magnetic force only occur, in a magnetic field, when a particle is moving perpendicularly relative to the magnetic field. So, all three quantities are perpendicular among themselves.
The Right-Hand Rule apply for the positive charges moving in conventional current. If the moving charge is negative, the velocity must be reversed.
Right-Hand Rule determines the direction of any or all of the three and it is as follows: With you right hand, point your index finger in the direction of the velocity, your middle finger in the direction of the magnetic field and your thumb will be pointing in the direction of the magnetic force.
Another way of using the rule is when there is a current carrying wire:
The fingers of your right hand will curl into a half circle around the wire, they will point in the direction of the field. The thumb will point in the direction of the conventional current.
As you said, the speed is constant in a vacuum, so the speed does not change, The frequency, on the other hand, decreases by half. The wavelength, λ (lambda), the frequency, v, and the speed of light, c, are related by the equation λν = c. We can see that frequency and wavelength are inversely proportional, so an increase in wavelength has a corresponding decrease in frequency.
iron, cobalt and Nickel is the answer
