Moderate -0.3 This is a straightforward application of the power equation P = Fv, requiring students to find the driving force using F = ma + resistance, then substitute into the power formula. It's a standard M1 question with clear given values and a direct method, making it slightly easier than average but still requiring correct application of multiple mechanics principles.
A car of mass 900 kg travels along a horizontal straight road with its engine working at a constant rate of \(P\) kW. The resistance to motion of the car is 550 N. Given that the acceleration of the car is \(0.2 \text{ m s}^{-2}\) at an instant when its speed is \(30 \text{ m s}^{-1}\), find the value of \(P\). [4]
A car of mass 900 kg travels along a horizontal straight road with its engine working at a constant rate of $P$ kW. The resistance to motion of the car is 550 N. Given that the acceleration of the car is $0.2 \text{ m s}^{-2}$ at an instant when its speed is $30 \text{ m s}^{-1}$, find the value of $P$. [4]
\hfill \mbox{\textit{CAIE M1 2007 Q1 [4]}}