Expressing Quantities & SI Units (Edexcel GCSE Physics)

State the unit for energy.

The unit for energy is a derived unit.

State the SI base units for the unit of energy.

A beaker containing 0.513 kg of water was heated by 18.4°C.

The specific heat capacity of water is 4200 J/kg °C.

Calculate the amount of energy transferred to the water. 

Give your answer to 2 significant figures.

Use the equation

energy transferred =  .................................... J

Convert your answer to part (c) into kJ.

Figure 1 shows an incomplete table of prefixes. Complete the table by filling in the missing information.

 Figure 1

A gamma wave has a wavelength of 950 nm.

Calculate its frequency.

The speed of light in a vacuum is 

Use the equation

frequency =  .................................... Hz

Give your answer to part (b) in MHz.

State the SI base units for Hz.

Newton's second law of motion describes the relationship between force, , mass, , and acceleration, . 

The derived unit for force is the newton (N).

Using Newton's second law, determine the SI base units of force.

The equation for Newton's second law is

SI base units of force =  .................................... 

A penny of mass 2.47 g was dropped from a height.

Calculate the downward force acting on the penny. 

The acceleration in free fall is 9.81 m/s²

Give your answer to 3 significant figures. 

force =  .................................... N

Give your answer to part (b) using a suitable prefix.

The temperature on that day was 28.3°C.

Give the temperature in kelvin.

 temperature =  .................................... K

Express the following numbers in scientific notation 

(i) 491

(1)

(ii) 54 070

(1)

(iii) 2 310 000

(1)

Express the following numbers in scientific notation 

(i) 0.011

(1)

(ii) 0.000503

(1)

(iii) 0.0000045

(1)

Express the following numbers in their original form 

(i) 4.031 × 10³

(1)

(ii) 6.7 × 10⁶

(1)

(iii) 7.71 × 10⁻⁵

(1)

Calculate the number of seconds in a leap year. 

number of seconds in leap year =  ................................. s

The wave equation describes the relationship between wave speed, , frequency, , and wavelength, .

UV rays travel at the speed of light and have a frequency of  .

Calculate the wavelength of the UV ray in nm.

The speed of light, 

Use the equation

 wavelength =  .................................... nm

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

(i) State the relevant SI base unit for time.

(1)

(ii) Convert 500 ms into the SI base unit.

500 ms =  ............................. unit ............................(1) 

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

Calculate the number of seconds in one year.

Give your answer to 2 significant figures and in scientific notation.

 one year =  .................................... s

Calculate the value of 1 light-year in m.

Use your answer from part (c) to help you.

Give your answer to 2 significant figures.

The speed of light in a vacuum,

 1 light-year =  .................................... m

Which row of the table correctly shows the prefixes in order of increasing value?

Which product pair of prefixes has the greatest magnitude?

Convert the following measurements into SI units using scientific notation.

i) 9.3 MJ to J

[1]

ii) 7.4 kW to W

[1]

iii) 10 mm to m

[1]

The newton is a derived unit. It is derived from the SI base units of kg m/s².

Deduce the SI base units for power.

A 1.2 GN force was applied across a distance of 32.4 cm. 

Calculate the work done.

Give your answer in standard form to 3 significant figures.

 work done =  .................................... J

The time taken for the 1.2 GN force to move a distance of 32.4 cm was 89.5 ms.

Calculate the energy transferred per unit time.

Give your answer in GW to 2 significant figures.

 energy transferred per unit time =  .................................... GW

Which of the following are the SI base units for gravitational field strength?

Which of the following are the SI base units for pressure?

The volt can be expressed as joules per coulomb, where 1 C = 1 A s.

Which of the following are the correct SI base units for resistance?