Forces and MotionIB MYP Physics: Topic test

20 questions, 54 marks

IB MYP Physics

Forces and Motion topic test

Total 54 marks

Name

Class

Date

1
A box of books weighing 80 N rests on a shelf in a library in Kuala Lumpur. Later, a librarian slides the box along the shelf.
(a)
What type of force is the weight of the box?
[1 mark]
AA contact force, because the box touches the shelf
BA non-contact force, because gravity acts without contact
CA contact force, because it acts on the shelf
DNo force, because the box is at rest
(b)
While the box is at rest, what is the force of the shelf on the box (the normal reaction)?
[1 mark]
A0 N, because the box is not moving
B80 N downwards
C80 N upwards
D160 N upwards
(c)
Suggest two ways to reduce the friction when the librarian slides the box along the shelf.
[2 marks]
Total for question 1: 4 marks
2
In a tug-of-war in Dhaka, team A pulls the rope to the left with a force of 1200 N and team B pulls it to the right with a force of 1050 N.
(a)
What is the resultant force on the rope?
[1 mark]
A150 N to the left
B150 N to the right
C2250 N to the left
D0 N
(b)
Considering only these two forces, what happens to the rope?
[1 mark]
AIt stays still because there are two forces
BIt moves to the right at a constant speed
CIt moves to the left at a constant speed
DIt accelerates to the left
(c)
Force is a vector. State what is meant by a vector, and give one example of a scalar quantity.
[2 marks]
Total for question 2: 4 marks
3
A spring in a luggage scale at an airport in Istanbul has a spring constant of 400 N/m. A suitcase hung from the spring stretches it by 0.050 m. Take g = 10 N/kg.
(a)
Calculate the weight of the suitcase.
[3 marks]
(b)
A second suitcase stretches the spring by 0.12 m. Calculate the mass of this suitcase, and state one condition that must be true for your calculation to be valid.
[4 marks]
Total for question 3: 7 marks
4
A lift in a tower in Dubai, with a total mass of 800 kg including its passengers, rises from rest. It speeds up uniformly to 6.0 m/s in 4.0 s, then moves at a constant 6.0 m/s for 10 s, then slows uniformly to rest in 3.0 s. Take g = 10 N/kg.
(a)
Calculate the tension in the lift cable during the first 4.0 s.
[6 marks]
(b)
Calculate the total height the lift rises, and state, with a reason, the tension in the cable while the lift moves at constant speed.
[6 marks]
Total for question 4: 12 marks
5
A camel in the Sahara has a weight of 6000 N. Each of its four feet has a contact area of 0.050 m².
(a)
What pressure does the camel exert on the sand when it stands on all four feet?
[1 mark]
A1500 Pa
B120 000 Pa
C300 Pa
D30 000 Pa
(b)
Why are the camel's wide feet useful on soft sand?
[1 mark]
AThey spread its weight over a larger area, so the pressure is lower and the feet sink less
BThey increase its weight, so it grips the sand
CThey increase the pressure on the sand, so the feet dig in
DThey reduce its mass
(c)
The camel lifts one foot off the ground while walking. Calculate the pressure under its three other feet.
[2 marks]
Total for question 5: 4 marks
6
A diver in the Maldives swims at a depth of 20 m in sea water of density 1030 kg/m³. Take g = 10 N/kg.
(a)
What is the pressure due to the water at this depth?
[1 mark]
A20 600 Pa
B2060 Pa
C206 000 Pa
D103 000 Pa
(b)
The diver swims down to a depth of 40 m. How does the pressure due to the water change?
[1 mark]
AIt stays the same
BIt doubles
CIt halves
DIt increases, but by less than double
(c)
State two factors that affect the pressure at a point in a liquid.
[2 marks]
Total for question 6: 4 marks
7
A gardener in Pune uses a wheelbarrow. The wheel axle acts as the pivot. The load in the wheelbarrow weighs 400 N and acts 0.40 m from the pivot. The gardener lifts the handles with a vertical force at a point 1.2 m from the pivot.
(a)
Calculate the moment of the load about the pivot.
[3 marks]
(b)
Calculate the force the gardener must apply to hold the handles level, and explain why it is less than the weight of the load.
[4 marks]
Total for question 7: 7 marks
8
In a crash test in Copenhagen, a dummy's head of mass 5.0 kg hits the ground at 8.0 m/s and is brought to rest. With a hard shell only, it stops in 0.010 s. With a foam-lined helmet it stops in 0.030 s. A government is deciding whether to make cycle helmets compulsory.
(a)
Calculate the momentum of the head just before impact and the average force on it in each case. Explain why the foam lining reduces the risk of injury.
[6 marks]
(b)
Discuss whether the government should make cycle helmets compulsory.
[6 marks]
Total for question 8: 12 marks

End of questions

Written by the Exaim team, led by Shaun Daswani (Head of Upper Secondary, Improve ME Institute; MSc Financial Mathematics, Imperial College London; BSc, UCL) and Jason Daswani (operational lead, Improve ME Institute; LSE).