The battery for a certain cell phone is rated at 3.70 V. According to the manufacturer it can produce math]3.15 \times 10^{4} J[/math] of electrical energy, enough for 5.25 h of operation, before needing to be recharged. Find the average current that this cell phone draws when turned on.

The average current that this cell phone draws when turned on is 0.451 A.

Explanation:

Given;

voltage of the phone, V = 3.7 V

electrical energy of the phone battery, E = 3.15 x 10⁴ J

duration of battery energy, t = 5.25 h

The power the cell phone draws when turned on, is the rate of energy consumption, and this is calculated as follows;

where;

P is power in watts

E is energy in Joules

t is time in seconds

The average current that this cell phone draws when turned on:

P = IV

Therefore, the average current that this cell phone draws when turned on is 0.451 A.

Step-by-step explanation:

Get the perimeter of the each shape and add it all up to get the total fencing material required.

2 square flower beds = 2 x 4a = 8a

1 rectangular play ground = 2l + 2w 

total fencing material = 8a + 2l + 2w