Explanation:
Given parameters:
Distance = 15miles north = 24140.2m
Initial velocity = 0m/s
Final velocity = 4m/s
Unknown:
Speed, velocity and acceleration = ?
Solution:
The speed is the distance divide by time. It is a scalar quantity and has no directional attribute.
Speed =
The speed of the student is 4m/s
Velocity is the displacement divided by time. It is a vector quantity which specifies the direction and magnitude;
Velocity =
The velocity of the student is 4m/s due north
Acceleration is the change in velocity with time;
To find the acceleration, we use
v² = u² + 2as
v is the final velocity
u is the initial velocity
a is the acceleration
s is the distance
4² = 0² + 2x a x 24140.2
a =
= 0.00033m/s²
Answer:
Current = dQ/dt
or I = dQ/dt
Where I represents current.
Which is the rate of flow of charge.
Q=4 + 2t + t²
dQ/dt = 2 + 2t --- This is the relation that gives the instantaneous current.
At time t=2sec
dQ/dt = I = 2 + 2t
= 2 + 2(2)
=2 + 4
= 6A.
There's a crest and a trough in each complete wave. So the question is describing 10 complete waves.
After that, the question becomes somewhat murky. It goes on to say "its time period is 0.2 seconds".
-- The "time period" of a wave is usually defined as the time for <u><em>one</em></u> complete wave. If that's what the phrase means, then ...
Frequency = ( 1/0.2sec )
<em>Frequency = 5 Hz.</em>
<em>= = = = = = = = = =</em>
<u>BUT</u> ... Is the question awkwardly trying to tell us that the <u><em>10 waves</em></u> take 0.2 seconds ? If that's what it's saying, then ...
Frequency = (10) / (0.2 sec)
<em>Frequency = 50 Hz .</em>