Question

5 formula 1 point
what is the power rating of a motor that is able to accelerate a 1,612 kg car from zero to 19.5 m/s in 0.7 seconds?
report your answer to 2 decimal places. your permitted error is ±0.01 w.
answer

Explanation:

Step1: Calculate the kinetic energy

The formula for kinetic energy is \(K = \frac{1}{2}mv^{2}\), where \(m = 1612\space kg\) and \(v=19.5\space m/s\).

$$
LATEXBLOCK0
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Step2: Calculate the power

Power \(P=\frac{W}{t}\), and here \(W = K\) (work - energy theorem, work done is equal to the change in kinetic energy, and initial kinetic energy is \(0\) as initial velocity \(u = 0\)). \(t = 0.7\space s\)

$$ P=\frac{306481.5}{0.7}=437830.714286\space W $$

Answer:

\(437830.71\space W\)