1. A carpenter applies a force of 60N horizontally to push a plane 40 cm along a...
Question:
1. A carpenter applies a force of 60N horizontally to push a plane 40 cm along a piece of wood, how much work does she do? (4)
2. A 90 KW motor exerts a force of 4.0 kN to move a speedboat at a constant speed. How fast is the boat moving? 940
Thinking (14 marks)
3. A 75 kg passenger in a car is wearing a seatbelt when the car, moving at 15 m/s collides with a concrete wall. The front of the car collapses 0.50 m as it comes to rest
a) What is the passenger’s kinetic energy before the collision? (4)
b) What average force did the seatbelt exert on the passenger during the
collision? (5)
4. A swimming pool contains 24 t of water at 15° C What is the final temperature if 30 t of water at 35 °C is added to the pool? (5)
Communication (5 marks)
5. Which of the following factors affect the amount of work needed to lift a heavy suitcase onto a high bed? Explain each answer!
a) The height of the bed
b) The mass of the suitcase
c) Whether the room is on the Earth or the Moon
d) Whether the suitcase is lifted straight up or on a diagonal
Application (18 marks)
6. A ramp is used to load crates onto a rail car. The length of the ramp is 6.0 m. The platform of the railcar is 1.5 m above the ground. Each crate has a mass of 450 kg. A force of 2025 N is applied parallel to the ramp to push the crate at a
constant speed up the ramp. Calculate:
a) The useful work done moving the crate up the ramp? (5) b) The actual work done moving the crate up the ramp? (4) c) The actual mechanical advantage of the ramp?(5)
d) The efficiency of the inclined plane? (4)
Physics
ISBN: 978-0077339685
2nd edition
Authors: Alan Giambattista, Betty Richardson, Robert Richardson