An electric device delivers a current of [tex]$15.0 A$[/tex] for 30 seconds. How many electrons flow through it?
Answer (2)
Approximately 2.81 x 10^21 electrons flow through the electric device when a current of 15.0 A is delivered for 30 seconds. This is calculated using the relationship between current, charge, and the charge of a single electron. The total charge over that period is 450 C, which we divide by the charge of one electron to find the number of electrons.
;
a. Table of Values for the Cost of Petrol
To create a table showing the cost of 2, 3, 4, 5, and 6 liters of petrol when 1 liter costs N1,100.00:
Quantity of Petrol (liters)Total Cost (Naira)22 x 1100 = N2,20033 x 1100 = N3,30044 x 1100 = N4,40055 x 1100 = N5,50066 x 1100 = N6,600
b. Drawing the Graph
Use the designated scales: 2 cm to 1 liter on the horizontal axis and 2 cm to N1,000.00 on the vertical axis. Plot these points on the graph:
(2, 2200)
(3, 3300)
(4, 4400)
(5, 5500)
(6, 6600)
Draw a straight line through these points to illustrate the linear relationship between the quantity of petrol and its cost.
c. Extending the Line on the Graph
i. Determining the cost of 7½ liters of petrol:
Extend the line on the graph to the point corresponding to 7.5 liters on the horizontal axis. The cost at this point should be around:
7.5 × 1100 = N 8 , 250.
ii. Determining how many liters can be bought with N3,500.00:
Extend the line on the graph to the point where the vertical axis shows N3,500. Determine the corresponding number of liters on the horizontal axis, which should be around:
1100 3500 ≈ 3.18 liters.
