AQA AS Physics

Topic Questions

1.1 Use of SI Units & Their Prefixes

1a3 marks

Scientists around the world use the same internationally agreed system of units. These are called the fundamental (base) SI units and are listed in Table 1

Table 1

Quantity

Name

Symbol

length

 

 

 

kilogram

 

 

 

s

 

ampere

 

temperature

 

K

amount of substance

 

mol

luminous intensity

candela

cd

Complete the missing quantities, names and symbols in Table 1.           

1b2 marks

 Use the equation linking kinetic energy and speed to write 1 Joule in SI unit. 

1c2 marks

Use the equation Charge = Current × Time to write 1 Coulomb in SI units.

1d2 marks

Use the equation Energy = Charge × Potential Difference to write 1 volt in SI units.

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2a4 marks

Convert the following measurements into standard form

         9.3 MJ = __________ J

         7.4 kW = __________ W

         10 mm = __________ m

         5.3 nC = __________ C

2b2 marks

Complete the names of the unit prefixes and their corresponding multiplier in Table 2.

Table 2

Unit prefix

Multiplier

 

10–9

milli

 

 

109

 

1012

deci

 

kilo

 

 

10–6

2c3 marks

Calculate how many times bigger 1 GJ is than 1 µJ.

2d3 marks

Calculate how many times smaller 1 nHz is than 1 kHz.

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3a1 mark

State the SI base unit for temperature.

3b3 marks

Convert the following:

      300 K to Celsius (ºC) = __________ ºC

      –70 ºC to Kelvin (K) = __________ K

      150 ºC to Kelvin (K) = __________ K

3c2 marks

The temperature unit of Fahrenheit (ºF) is commonly used in the U.S.A.   

Use the equation F a r e n h e i t space equals space 9 over 5 C e l s i u s space plus space 32 to convert the following into  ºF: 

      50 ºC = __________ ºF

      –24 ºC = __________ ºF

3d2 marks

Wein’s law states that black-body radiation from stars for different temperatures will peak at difference wavelengths. The absolute temperature at any peak wavelength is defined by the equation:

            ? =fraction numerator 2.9 cross times 10 to the power of negative 3 space m space K end exponent over denominator lambda subscript m a x end subscript end fraction

Where:

  • λmax is the maximum wavelength (m)
  • T = Absolute temperature (K)

Our Sun has a peak wavelength in the visible range at around 500 × 10–9 m. 

Calculate the absolute temperature of the Sun in ºC.

   

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4a2 marks

UV rays travel at the speed of light and at a frequency of 900 × 1012 Hz.

Use the equation wavelength = velocity ÷ frequency to calculate the wavelength of the UV ray in nm.

4b2 marks

UV rays travel from the Sun to the Earth in 500 ms.

State the relevant SI base unit for time and convert the given value to its base unit.

4c2 marks

Convert 1 year into seconds in standard form.

4d2 marks

A light year is the distance light travels in a year.

d)
Use the equation distance = speed × time to calculate the value of 1 light year in km.

 

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5a2 marks

Use the equation linking force and acceleration to write 1 Newton in SI units.

5b3 marks

Use the equation Pressure = Force ÷ Area to write 1 Pascal in SI units.

5c2 marks

A ballet dancer applies a pressure of 1.7 × 104 Pa on an area of 0.3 m2 of a floor.

Use the equation Force = Pressure × Area to calculate the force applied in kN.

  

5d4 marks

Rearrange the following forces in decreasing magnitude

               1 MN, 1 mN, 1 pN, 1 TN

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1a3 marks

The Tesla, symbol T, is the unit of magnetic flux density.

Use the equation Force = Magnetic flux density × Current × Length write 1 Tesla in SI units.

 

1b4 marks

Complete Table 1 by converting the following measurements into their appropriate SI unit and express to an appropriate number of significant figures.

Table 1

 

Value

SI Unit

7 kWh

 

 

81.6 hours

 

 

1c3 marks

1 eV is the amount of kinetic energy gained by a single electron accelerating from rest through a potential difference of 1 V.

1 eV = 1.60 × 10-19 J.

Convert 0.01 kWh into TeV.

 

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2a4 marks

Convert the following measurements to the appropriate unit, and express to an appropriate number of significant figures.

   60000 GW = ____________ MW

   25.8 µF = _____________ pF

   0.19 fm = _____________ km

   416 minutes = ____________ms

2b2 marks

A sheet of silver has a thickness of 0.671 µm. A silver atom has a radius of 172 pm.

Approximately how many layers of atoms are there in this sheet ?

   

2c4 marks

A silver block of volume 0.67 cm3 is used to a make a silver ring of mass 7 g. 

State the appropriate SI unit for density and calculate the density of silver in this unit.

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3a4 marks

Tensile stress (σ) is defined as the force applied per unit cross-sectional area on a material. The tensile strength is the maximum amount of tensile stress a material can be subjected to before fracturing. 

The humerus bone is approximately cylindrical and has a tensile strength of 0.17 GPa and a diameter of 20 mm. 

Calculate the maximum force on the humerus bone before it fractures.    
3b4 marks

The femur bone is the strongest bone in the body. It has a tensile strength of 0.135 kN mm2.

Calculate the tensile strength of the femur bone in MPa.

    

3c3 marks

Calculate the number of cubic millimetres (mm3) in 15 km3

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4a4 marks

The distance time graph for a lorry travelling at constant speed is shown in Figure 1.

 1-1-s-q--q4-hard-aqa-a-level-physics

a)
 Calculate the speed of the lorry in m s1.

  

4b3 marks

The velocity-time graph of a different lorry is shown in Figure 2.

1-1-s-q--q4-b-hard-aqa-a-level-physics

Calculate the distance the lorry travels in m.

  

4c4 marks

Calculate the acceleration of the lorry in Figure 2 into the appropriate SI unit.

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5a4 marks

Estimate the order of magnitude with an appropriate SI unit and correct prefix for the following quantities in Table 1. 

Table 1

Quantity

Order of magnitude

Mass of an aeroplane

 

Radius of a proton

 

Current through an LED

 

Time between two heart beats

 

5b4 marks

The equation Energy = Mass × (Speed of light)2­ demonstrates that energy and matter are interchangeable.

 1 u is the atomic mass unit and a common unit used in nuclear physics.

 1 u is equal to 931.5 MeV, where 1 eV= 1.60 × 10-19 J .

Show that its value in kg is approximately equal to the mass of a proton in kg.

   

5c4 marks

The cross-sectional area of nuclei is commonly measured in units of ‘barn’, symbol b.

 1 barn = 100 fm2

Calculate the value of a nano barn (nb) in m2

      

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1a3 marks

Use the equation Capacitance = fraction numerator C h a r g e over denominator P o t e n t i a l space D i f f e r e n c e end fraction   to write 1 Farad [F] in SI base units.

1b3 marks

A parallel plate capacitor of capacitance 75μF is connected to a 5 kV power supply.

Using the equation Charge = Potential difference × Capacitance, calculate the charge between the plates in mC.

1c4 marks

Rearrange the following capacitance in increasing magnitude:

             1 pF, 1 µF, 1 cF, 1 fF

1d2 marks

Estimate the current through an 1800 W kettle connected to a UK mains supply using the equation Power = Potential difference × Current 

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2a4 marks

Convert the following measurements into standard form.

   40000 kJ = ________________ J

   0.23 GW = _______________ W

   1.15 fm = ______________ m

   72.6 pC = _______________ C

2b4 marks

X-rays from a pulsar travel at the speed of light and are detected on earth with a wavelength of 5 nm. 

Using an appropriate equation, calculate the frequency of the X-rays in THz.

    

2c1 mark

X-rays from the nearest pulsar PSR J0109-1431 take 8.82 Gs to travel to Earth. 

Calculate the time it takes for the X-rays to reach Earth in seconds.        
2d3 marks

Show the distance from Earth to PSR J0109-1431 is around 280 light years.

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3a3 marks

Use the hydrostatic pressure equation to write 1 Pascal [Pa] in SI base units.

3b4 marks

A box is placed on the floor. The area of the box in contact with the floor is 4.9 cm2. The pressure exerted on the floor is 20 kPa. 

Using the equation linking Pressure, Force and Area, calculate the force exerted by the box on the floor. 

3c2 marks

Atmospheric pressure on Earth is 101 325 Pa. The Mariana trench at the bottom of the western Pacific Ocean has a pressure of around 110 MPa.

Calculate how many times larger the pressure of the Mariana trench is than the atmospheric pressure on Earth.
3d3 marks

Rearrange the following in order of decreasing pressure:

  • Atmospheric pressure at the summit of Mount Everest
  • Surface pressure on the Moon
  • Atmospheric pressure ~ 101 kPa
  • Water pressure of an average garden hose
  • The Mariana trench ~ 110 MPa

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4a3 marks

Use the equation linking Power, Current and Potential difference to write 1 Watt [W] in SI base units.

4b4 marks

Kilowatt-hour (kWh) is a unit of energy.

Using the equation linking Energy, Power and Time, convert 1 kWh to Joules.

4c1 mark

Convert your answer from part (b) into MJ.

4d4 marks

A 5.1 kW hair dryer is used for 45 minutes. The electricity bill is charged as 8 p per kWh used.

Calculate the cost of using the hairdryer in pounds.

  

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5a2 marks

Use the equation linking Force, Momentum and Time to write 1 Newton in SI units.

5b5 marks

To leave Earth, a rocket must travel at around 8 km s–1.

Calculate the thrust on a rocket which ejects 2.3 × 104 kg of waste gas per second to leave Earth in MN. Show all your working clearly.

5c2 marks

A rocket can hold 20 000 kg of material.

Calculate how many rockets would be needed to deliver 60 tonnes of material to a space station.

     

5d2 marks

Estimate the impulse on a tennis ball travelling at 70 m s–1 as it hits a racket.

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