Problem 1: You are practicing for an ocean kayak expedition in a local pool. You
ID: 1788664 • Letter: P
Question
Problem 1: You are practicing for an ocean kayak expedition in a local pool. You, your kayak, and a backpack of supplies that you have stored in the front of the kayak are floating in the pool. You have a mass of 60 kg, your kayak is 20 kg and your backpack that has a volume of 20 litres is stuffed full of supplies and has a mass of 30 kg. a) What volume of water do you, your kayak and bag of supplies displace while floating? (1 mark) b) Given your backpack's volume and mass, would it float in water? (1 mark) c) You do a roll and return to the upright position. During the roll your backpack fell out and went into the pool. What happens to the level of water in the pool? does it go up, down or stay the same? Why? (2 marks)Explanation / Answer
a) In the equilibrium,
Buoyant force = weight of you + kayak + backpack
B = (m_you + m_kayak + m_backpack)*g
rho_water*V_water*g = (m_you + m_kayak + m_backpack)*g
V_water = (m_you + m_kayak + m_backpack)/rho_water
= (60 + 20 + 30)/1000
= 0.11 m^3
b) No. because the density of back pack = 30 kg/20 L
= 1.5 kg/L or 1500 kg/m^3 > density of water.
c) Stays the same. The volume of water dispalced by the backpack in both cases is same.