When a car of mass $1167 \mathrm {~kg}$ accelerates from 10.0 m/s to some final speed,4.00 × 10⁵ J of work are done on it by the frictional force exerted on the car by the road's surface.Find this final speed. A)28.0 m/s B)22.4 m/s C)25.2 m/s D)30.8 m/s

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Quizplus · Accepted Answer

The work done on the car is equal to the change in its kinetic energy:$$W_{nc}=\frac{1}{2}mv_f^2-\frac{1}{2}mv_i^2$$$$4.00	imes10^5	ext{ J}=\frac{1}{2}(1167	ext{ kg})v_f^2-\frac{1}{2}(1167	ext{ kg})(10.0	ext{ m/s})^2$$$$v_f=\boxed{28.0	ext{ m/s}}$$

When a Car of Mass 1167 kg1167 \mathrm {~kg}1167 kg Accelerates from 10

When a Car of Mass $1167 \mathrm {~kg}$ Accelerates from 10