A sled of mass 10 kg starts out at an initial speed of 5 m/s on a horizontal surface.The coefficient of kinetic friction with the snow is 0.05.Use energy considerations to determine how far it goes before it comes to a stop (within 5% accuracy).

Question

Quizplus · Accepted Answer

The work done by friction (which equals the change in kinetic energy since the sled comes to a stop) can be calculated using the formula $W = F_{\text{friction}} \times d$, where $F_{\text{friction}} = \mu_k \times m \times g$, and $W = -\Delta KE = -\frac{1}{2}mv^2$. Plugging in the given values: $W = -\frac{1}{2} \times 10 \times (5)^2 = -125 \, \text{J}$, and $F_{\text{friction}} = 0.05 \times 10 \times 9.8 = 4.9 \, \text{N}$. Solving for $d$, we get $d = \frac{-W}{F_{\text{friction}}} = \frac{125}{4.9} \approx 25.5 \, \text{m}$, which is within 5% accuracy of choice A.

A Sled of Mass 10 Kg Starts Out at an Initial