Question

help me in physics

Answer 1

@IrishBoy123

Answer 2

@uri

Answer 3

I can't really help you since some of the question is cut off, so I really don't know what they are asking you, sorry!

Answer 4

when a certain 1.5 V battery is used to power a 3.0 W flashlight bulb it is exhausted after an hours use. a. how much chargedhas passed through the bulb in this period of time? b. if the electric energy obtained in this way? c. how does this comparewith the cost of the electric energy supplied to your home which is
about php 11.50/kwh

Answer 5

@Michele_Laino

Answer 6

we have to compute the intensity of current which flows into your flashlight bulb, first

Answer 7

yes,

Answer 8

the intensity of current, is given by the subsequent relationship:
\[\Large I = \frac{W}{V}\]
where W is the power, and V is the voltage applied to our flashlight bulb

Answer 9

so 3.0/1.5 = 1.5

Answer 10

that's right! The current is 1.5 amperes

Answer 11

so whats next

Answer 12

Now, the requested charge Q, is given by the subsequent formula:
\[\Large Q = I \times \Delta t\]
where \Delta T is time, measured in seconds, and Q is measured in Coulombs

Answer 13

theres no given time

Answer 14

1 hour only

Answer 15

time is 1 hours=3600 seconds

Answer 16

hour*

Answer 17

yes so, 1.5 A (3600s( = 5400

Answer 18

that's right! Total charge is Q=5400 coulombs

Answer 19

ys

Answer 20

next is the battery cost

Answer 21

now, the energy E absorbed by our flashlight bulb is given by the subsequent formula:
\[\Large E = W \times \Delta t = 0.003 \times 1 = ...?{\text{kWh}}\]
please note that I have measured the power in KWatt, and time in hour, in order to get the energy in kWh

Answer 22

= 3x10-3

Answer 23

since 3 Watt= 3/1000=0.003 kWatt

Answer 24

that's right!

Answer 25

now, in order to get the total cost, you have to multiply that energy by the specific cost, namely 11.50, so we have:
\[\Large {\text{total cost }} = {\text{ }}11.50 \times 3 \times {10^{ - 3}} = ...?\]

Answer 26

= 0.0345 php

Answer 27

that's right!

Answer 28

what abot the if the battery cost 9 php

Answer 29

that means our flashlight bulb can be powered, with that battery for at least
9/0.0345=...? hours

Answer 30

my problem is incomplete when a certain 1.5 V battery is used to power a 3.0 W flashlight bulb it is exhausted after an hours use. a. how much chargedhas passed through the bulb in this period of time? b. if the battery cost Php 9.00 , what is the cost of a kilowatt hour of electric energy obtained in this way? c. how does this comparewith the cost of the electric energy supplied to your home which is
about php 11.50/kwh

Answer 31

thats the problem

Answer 32

in that case, in order to find the specific cost, we have to compute this:
\[\Large \frac{9}{{0.003}}\]

Answer 33

whats the formula used

Answer 34

=3000

Answer 35

cost of battery/ absorbed energy

Answer 36

that's right!

Answer 37

whats the unit

Answer 38

php/kWh

Answer 39

ojkay then how about letter b

Answer 40

i mean c

Answer 41

here it is suffice to compute this ratio:
\[\frac{{3000}}{{11.50}} = ...?\]

Answer 42

= 280.87, whats the formula

Answer 43

I got 260.87. I used this formula:
\[\Large \frac{{{\text{specific cost using battery}}}}{{{\text{specific cost using electricity of home}}}}\]

Answer 44

that ratio indicates taht the electricity supplied by battery is more expensive than the electricity supplied by the home electricity

Answer 45

ah yes its 260.87 what should be the explanation

Answer 46

yes!

Answer 47

tthankyou very very much

Answer 48

thank you! :)