Problem 12 : A student m = 84 kg runs at a velocity v i = 2.4 m/s before jumping
ID: 2262780 • Letter: P
Question
Problem 12: A student m = 84 kg runs at a velocity vi = 2.4 m/s before jumping on a skateboard. After jumping on the board the student has a velocity vf = 1.88 m/s.Randomized Variablesm = 84 kg
vi = 2.4 m/s
vf = 1.88 m/s Part (a) Write an expression for the weight of the skateboard W.
Part (b) What is the mass of the skateboard in kg?
Part (c) The student soon loses his balance and falls backwards off the board at a velocity of 4 m/s. What is the skateboards new velocity in m/s? A student m = 84 kg runs at a velocity vi = 2.4 m/s before jumping on a skateboard. After jumping on the board the student has a velocity vf = 1.88 m/s. m = 84 kg vi = 2.4 m/s vf = 1.88 m/s Write an expression for the weight of the skateboard W. What is the mass of the skateboard in kg? The student soon loses his balance and falls backwards off the board at a velocity of 4 m/s. What is the skateboards new velocity in m/s?
Explanation / Answer
conserving the momentum
84*2.4=(84+m)*1.88
==> m=23.23 Kg(mass of scate board
now
84*2.4=-84*4+23.23*v
==> v=23.14 m/s (final velocity of scateboard)