Return Sub 6 1 point A child (mc=21.0 kg,msled=15 kg) is sledding down an icy hill (h=4.2 m)where friction does not matter. The child has an initial speed of vi=4 m/s. When the child gets to the bottom of the hill, they slide until they reach a patch of gravel 8.6 m wide. The coefficient of friction between the sled and the gravel is JK=0.50. After they go through this gravel, they are back on a frictionless surface again. Follow the steps exactly how they are written for grading purposes. h = 4.2m Ax = 8.6 m A: We will first use energy conservation to find the speed of the child at the bottom of the hill. i: Choose a closed system: ii: What energy changes are occurring in the system you chose? AE= iii: Find the final velocity of the child at the bottom of the hill. B: Now we are going to find the acceleration of the child and sled across the gravel. i: Draw a correct free-body diagram of a system consisting of the child and the sled. ii: Write the Fnet equation for the x and y directions. iii: Solve the Fnet,x equation for the acceleration of the system. iv: Using kinematics find the final velocity of the child after they have gone through the gravel. You have an initial velocity, an acceleration, and a distance. There is one kinematics equation we have used a lot with these three things in it. Remember that your acceleration is negative. Might want to check that above. C: Our new closed system will be child, sled, and Earth (friction is now internal to the system). i: Write down the energy changes taking place (friction causes something to happen): AE= ii: Using K=1/2 mv calculate the change in Kinetic energy of the system. I will be looking for correct signs in this. iii: How much thermal energy did the friction generate? Explain why vou know in no more than ? sentences Q Search PC ENG 12