Answer to Question #44687 in Physics for Camilla

Question

(a) Assume your heart uses 1.2 J of energy per heartbeat.?

(i) Write down a plausible number for the rate (i.e. number of times per second)
at which your heart is beating now. [2]
(ii) What is the rate at which your heart uses energy per second (in J s−1
) ?
[2]
(iii) If you live to be 90 years old, how many heartbeats would you have had ? [2]
(b) Your brain uses energy at a rate of ∼ 1.5 × 106
J per day.
(i) What is the rate at which which your brain uses energy per second ? [2]
(ii) Over the course of this exam, how much energy will your brain have used ?

Seems easy enough,but just can't get it right.

Thank you ! :)