- #1
abruski
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Homework Statement
A car with mass m = 1 metric ton (1000 kg) in time t = 5 seconds reaches speed v = 20 m/s
What is the power of the car? P = ? kW (kilo Watts)
Homework Equations
F - force, a - acceleration, A - work, s - distance
[tex]P = \frac{A}{t}[/tex]
[tex]P = Fv[/tex]
[tex]F = ma[/tex]
[tex]a = \frac{v}{t}[/tex]
[tex]A = Fs[/tex]
[tex]s = vt[/tex]
The Attempt at a Solution
The answer given in the book is 40 kW but I get 80 kW. With the 40 kW I get that the acceleration s 2 m/s[tex]^{2}[/tex], which means that
[tex]\frac{v}{t} = \frac{20}{5} = 2[/tex]
??
Maybe I miss something. Any help is appreciated.