A20-kg sled is being pulled along the horizontal snow-covered ground by a horizontal force of 26 n. starting from rest, the sled attains a speed of 2.3 m/s in 8.9 m. find the coefficient of kinetic friction between the runners of the sled and the snow.

Good morning.

We calculate the acceleration with the Torricelli equation:



We see that:



Now:



Now we can calculate the resultant force that makes that acceleration of 0.3 m/s² with the 2nd Law of Newton:



We have a force of 26 N → and a friction force F ←. Adding those vectors, he have  a force 6 N →. Therefore:

26 - F = 6

F = 20 N

We have a friction force of 20 N. We calculate the kinect coefficient with the formula:



Since we are in a horizontal plane, we hava that N = P = mg = 200 N

Therefore:

The reflection of the candle in the concave mirror formed an upside-down virtual image that is smaller than the candle.in other words. the answer is the third option, c