Answer:
Explanation:
The acceleration of gravity is 9.8m/s^2.
So to calculate the time it will take to make the ball stop(which btw means the ball now reach its greatest height), use the formula V1=V0+at. V1 is the final velocity(which is 0), V0 is the starting velocity(which is 30m/s), and the a(cceleration) is 9.8m/s^2.
(You can ignore the fact "at" is -30 instead 30, it's because the directions two velocity travel are opposite. )
We can now know the time it takes to make the ball stop just by the gravitational force is about 3 sec.
Use another formula S=1/2at^2, to find out the S(height) is 1/2*9.8*3^2=44.1, which is approximately D.45m .
Explanation:
see the above attachment to solve the question and get the answer.
hope this helps you.
The right hand rule to find the direction of the magnetic field for a falling bar is:
- The charge is positive the magnetic field is outgoing, horizontally and towards us.
- The charge of the bar is negative, the magnetic field is incoming, that is horizontal away from us.
The magnetic force is given by the vector product of the velocity and the magnetic field.
F = q v x B
Where the bolds indicate vectors, F is the force, q the charge on the particle, v the velocity and B the magnetic field.
In the vector product, the vectors are perpendicular, which is why the right-hand rule has been established, see attached:
- The thumb points in the direction of speed.
- Fingers extended in the direction of the magnetic field.
- The palm is in the direction of the force if the charge is positive and in the opposite direction if the charge is negative.
They indicate that the bar is dropped, therefore its speed is vertical and downwards, it moves to the left therefore this is the direction of the force, we use the right hand rule, the magnetic field must be horizontal, we have two possibilities:
- If the charge is positive the magnetic field is outgoing, horizontally and towards us.
- If the charge of the bar is negative, the magnetic field is incoming, that is, horizontal away from us
In conclusion using the right hand rule we can find the direction of the magnetic field for a falling bar is:
- The charge of the bar is negative, the magnetic field is incoming, that is horizontal away from us.
- The charge is positive the magnetic field is outgoing, horizontally and towards us.
Learn more about the right hand rule here: brainly.com/question/12847190
The answer for the following answer is answered below.
- <u><em>Therefore the time period of the wave is 0.01 seconds.</em></u>
- <u><em>Therefore the option for the answer is "B".</em></u>
Explanation:
Frequency (f):
The number of waves that pass a fixed place in a given amount of time.
The SI unit of frequency is Hertz (Hz)
Time period (T):
The time taken for one complete cycle of vibration to pass a given point.
The SI unit of time period is seconds (s)
Given:
frequency (f) = 100 Hz
wavelength (λ) = 2.0 m
To calculate:
Time period (T)
We know;
According to the formula;
<u>f =</u>
<u></u>
Where,
f represents the frequency
T represents the time period
from the formula;
T = 
T = 
T = 0.01 seconds
<u><em>Therefore the time period of the wave is 0.01 seconds.</em></u>