An electric toy with a resistance of 2.50 Ω is operated by a 3.00-V battery. (a) What current does the toy draw? (b) Assuming that the battery delivers a steady current for its lifetime of 4.00 h, how much charge passed through the toy? (c) How much energy was delivered to the toy?

Question

Physics

Rodney Sweeney

27 June, 12:22

An electric toy with a resistance of 2.50 Ω is operated by a 3.00-V battery. (a) What current does the toy draw? (b) Assuming that the battery delivers a steady current for its lifetime of 4.00 h, how much charge passed through the toy? (c) How much energy was delivered to the toy?

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Answers (1)

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Kayley Allen · Answer 1

a) The current is i = 1.2 A

b) The charge is Q = 17280 C

c) The energy is E = 43200 J

Explanation:

a) The current is given by the ohm's law wich is:

i = V/R = 3/2.5 = 1.2 A

b) Since the charge is steady we can use the following equation to find the charge amount in that time:

i = Q/t

Q = t*i

Where t is in seconds, so we have 4h * 3600 = 14400 s

Q = 1.2*14400 = 17280 C

c) The energy is the power delivered to the toy multiplied by the time:

P = 1.2*2.5 = 3 W

E = P*t = 3*14400 = 43200 J