Answer: The velocity at different marked time points are given as
t1 = -
t2 = +
t3 = +
t4 = -
t5 = 0
Explanation:
The slope of the tangent of the curve indicates the instantaneous velocity. So if the slope of the tangent is positive, that Is, the tangent makes a positive angle (above the horizontal axis) with the horizontal
axis, then the velocity at this point is positive, and if the slope of the tangent is negative, that is the tangent makes a negative angle with the horizontal axis (below the horizontal axis), then the velocity at this point is negative.
When the tangent of the line is parallel to the horizontal axis, the velocity is 0.
From the position-time graph attached, the sign on the instantaneous velocity for each time marked on the graph is given below
t1 = -
t2 = +
t3 = +
t4 = -
t5 = 0
QED!
Answer:
Part (i)
Z = 39.06 ohm
Part (ii)
R = 21.7 ohm
Explanation:
a) here we know that
maximum value of EMF = 125 V
maximum value of current = 3.20 A
now by ohm's law we can find the impedence as

now we will have

Part b)
Now we also know that


now we have


Answer:

Explanation:
Given that,
The car traveled a total of 1,200 meters during this test.
We need to find the average speed of the car. The average speed of the car is given by total distance covered divided by the time taken. So,

But putting the value of t we can find the average speed of the car.
The force that pushes charges through a wire is called voltage. Electric
current is the movement of the electrons caused by potential difference. For example,
in a circuit, the electrons in the bulb will not move without the potential
difference or voltage. When there is voltage, electric current occurs because
there is a driving force for the electrons in the wire to move.