Question 1

Marks: 1

The frictional force F on a sphere falling through a fluid is given by the formula:

F = $6 π a η ν$

In this equation, a is the radius of the sphere, η is a constant relating to the fluid and v is the velocity of the sphere.

What are the units of η?

kg m s^–1
kg m^–1 s^–1
kg m s^–3
kg m^–3 s^–3

Key Concepts

SI Units

Question 2

Marks: 1

The speed v of a liquid leaving a tube depends on the change in pressure ΔP and the density ρ of the liquid. The speed is given by the equation:

v = k ${(\frac{∆ P}{ρ})}^{n}$

In this equation, k is a constant that has no units.

What is the value of n?

$\frac{1}{2}$
1
$\frac{3}{2}$
2

Key Concepts

SI Units

Question 3

Marks: 1

Which estimate is realistic?

The kinetic energy of a bus travelling on an motor way is 30 000 J
The power of a domestic light is 300 W
The temperature of a hot oven is 300 K
The volume of air in a car tyre is 0.03 m³

Key Concepts

Estimating Physical Quantities
Orders of Magnitude

Question 4

Marks: 1

The theory of gas flow through small diameter tubes at low pressures is an important consideration of high vacuum techniques.

One equation used in this theory is:

Q = $\frac{k r^{3} (p_{1} - p_{2})}{L} \sqrt{\frac{M}{R T}}$

Where k is a unitless constant, r is the radius of the tube, p₁ and p₂ are the pressures at each end of the tube, L is the length of the tube, M is the molar mass of the gas, R is the molar gas constant and T is the thermodynamic temperature of the gas.

What are the base units of Q?

kg s^–1
kg m s^–1
kg mol^–1
kg m s^–2

Key Concepts

SI Units

Question 5

Marks: 1

What is the correct value for the Gravitational constant?

6.67 × 10^–3 nN m² kg^–2
6.67 × 10⁵ N mm² kg^–2
6.67 × 10^–20 kN mm² kg^–2
6.67 × 10^–17 N km² kg^–2

Key Concepts

Scientific Notation & Metric Multipliers

Question 6

Marks: 1

A boy jumps from a wall 5 m high. What is an estimate of the change in momentum of the boy when he lands without rebounding?

4 × 10⁰ kg m s^–1
4 × 10¹ kg m s^–1
4 × 10²kg m s^–1
4 × 10³ kg m s^–1

Key Concepts

Estimating Physical Quantities

Question 7

Marks: 1

When a constant braking force is applied to a vehicle moving at speed v, the distance d moved by the vehicle as it comes to rest is given by the expression:

d = kv²

In this equation, k is a constant.

When d is measured in metres and v is measured in metres per second, the constant has a value of k₁.

What is the value of the constant when the distance is measured in metres, and the speed is measured in kilometres per hour?

$\frac{k_{1}}{12.96}$
$\frac{k_{1}}{3.6}$
3.6k₁
12.96k₁

Key Concepts

SI Units

Question 8

Marks: 1

What is the unit for the gas constant in fundamental SI units?

kg m s^–2 K mol^–1
kg m² s^–2 K^–1 mol^–1
kg² m² s^–1 K^–1 mol
kg m² s^–2 mol^–1

Key Concepts

SI Units

Question 9

Marks: 1

Which of the following gives the correct unit for $\frac{g^{3}}{G}$ ?

kg s^–4
kg^–1 s^–4
kg m³ s^–4
kg s^–8

Key Concepts

SI Units

Question 10

Marks: 1

The drag coefficient C_d is a number with no units. It is used to compare the drag on different cars at different speeds. It is given by the equation

C_d = $\frac{2 F}{ρ v^{n} A}$

F is the drag force on the car, ρ is the density of the air, A is the cross-sectional area of the car and v is the speed of the car.

What is the value of n?

1
2
3
4

Key Concepts

SI Units

DP IB Physics: SL

Topic Questions

1.1 Measurements in Physics

Question 1

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Question 2

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Question 3

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Question 4

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Question 5

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Question 6

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Question 7

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Question 8

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Question 9

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Question 10

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