Well, if you take x to be 25 seconds, there are 2.4x in 1min. So, that multiplied by 60, would be 144x. Therefore, 1/4 multiplied by 144x should be the answer.
Use compound interest formula F=P(1+i)^n twice, one for each deposit and sum the two results.
For the P=$40,000 deposit,
i=10%/2=5% (semi-annual)
number of periods (6 months), n = 6*2 = 12
Future value (at end of year 6),
F = P(1+i)^n = 40,000(1+0.05)^12 = $71834.253
For the P=20000, deposited at the START of the fourth year, which is the same as the end of the third year.
i=5% (semi-annual
n=2*(6-3), n = 6
Future value (at end of year 6)
F=P(1+i)^n = 20000(1+0.05)^6 = 26801.913
Total amount after 6 years
= 71834.253 + 26801.913
=98636.17 (to the nearest cent.)
Given:
Q = 0.0764 kJ = 764 J, heat input
W = -830 J, useful work done
From the 1st Law of Thermodynamics, the change in internal energy is
δE = Q - W
= 764 - (-830)
= 1594 J = 1.594 kJ
Answer: 1.59 kJ (two sig. fig.)
