Return 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. ili: 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 you know in no more than 2 sentences. T Drag n Drop here or Browse