Problem 7: A skateboarder with mass ms = 42 kg is standing at the top ofa ramp which is h), = 3.6 m above the ground. The skateboarder then jumps on his skateboard and descends down the ramp. His speed at the bottom of the ramp is sz 6.2 m/s. Part (2) Write an expression for the work, Wf, done by the friction force between the ramp and the skateboarder in terms of the variables given in the problem statement. Expression sz Select from the variables below to write your expression. Note that all variables may not be required. cos(9), sin(6), (1, [5,11, p, H, d, g, by, ms, P, t, Vf, Wf Part (b) The ramp makes an angle 49 with the ground, where 9 = 30\". Write an expression for the magnitude of the friction force,f}., between the ramp and the skateboarder. Expression Ff: Select from the variables below to write your expression. Note that all variables may not be required. cos(9):Sin(6)1 a, B, n, p, e. d, g, by. ms, P. t. vr, Wr Part (c) When the skateboarder reaches the bottom ofthe ramp, he continues moving with the speed vy'onto a at surface covered with grass. The friction between the grass and the skateboarder brings him to a complete stop after 5.00 m. Calculate the magnitude of the friction force, F grass in newtons, between the skateboarder and the grass. Numeric : A numeric value is expected and not an expression. F grass 2 Problem 8: A ball is suspended from a light 1.3 m string as shown. The string makes an angle of 25 degrees with the vertical. The ball is then kicked up and to the right such that the string remains taut the entire time the ball swings upwards. This kick gives the ball an initial velocity of 1.2 m/s. Part (a) What will be the speed, in meters per second, ofthe ball when it reaches its lowest point (9 = 0)? Numeric : A numeric value is expected and not an expression. v : Part (b) What will be the maximum angle, in degrees, the string will make with the vertical? Numeric : A numeric value is expected and not an expression. 6max 2 9101 AM Mon Oct 10 "5\" 100% - usb06ca.theexpertta.com i 8 E3 The Expert TA | Human-like Gradi... Ea Problem 4: The Slingshot is a ride for two people. It consists of a single passenger cage, two towers, and two elastic bands. Potential energy is stored in the elastic bands and the passenger cage is released. On the way up, this potential energy in the elastic bands is converted into the kinetic energy of the cage. At the maximum height of the ride, the energy has been converted into gravitational potential energy of the cage. The slingshot has two towers of height h : 72 m. The towers are a distance d : 31 m apart. i Each elastic band has an unstretched length of L0 = 41 m and a spring constant of k = 305 N/m. The total mass of the passengers and cage is m = 380 kg. The car is pulled '1 .' down to the ground in the middle of the two towers. Id 1 I Ihot-\\pcrlluxnm Part (a) Write an expression for the stretched length L of one of the elastic bands strung from the cage to the top of its tower. MultipleChoice : 1)ch ~ (612)2 )\"2-L0 2\"112.112 )1/2_L0 3) ( h2 -- d2 )1/2 4) h2+(df2)2 5)(112+(sz)2 )\"2 6) h2+d2 Part (1]) Calculate the stretched length, in meters, of each band. Numeric : A numeric value is expected and not an expression. L : Part (c) Write an expression for the total potential energy stored in the elastic hands before the cage is released. MultipleChoice : 1) [dz ( ( 112 + ((112)2 )\"2 - L0 )2 2) H2 ( 112 +(df2)2) 3) k (112 -. (i/2? ) 4) k (112 -. (df2)2 L0 )2 5) k ((h2 +(drz)2 )\"2-Lo)2 6) k (112 + (d/2)2)2 Part (d) Calculate the total potential energy, in joules, stored in the elastic hands before the cage is released. Numeric : A numeric value is expected and not an expression. U: Part (e) Calculate the maximum height, in meters, of the ride. Numeric : A numeric value is expected and not an expression. hf: Problem 5: A child of mass m : 22 kg slides down a slide of height h : 2.3 m without friction. Let gravitational potential energy be zero at ground level