1.11 Compound Measures - Speed, Density, Pressure

A car travels at a constant speed.
It travels a distance of 146.2 m, correct to 1 decimal place.
This takes 7 seconds, correct to the nearest second.

Calculate the upper bound for the speed of the car.

........................................... m/s

A train of length 105 m takes 11 seconds to pass completely through a station of length 225 m.
 
Calculate the speed of the train in km/h.
 

........................................ km/h

Liquid A has a density of 0.7 g/cm³.
Liquid B has a density of 1.6 g/cm³.

140 g of liquid A and 128 g of liquid B are mixed to make liquid C.

Work out the density of liquid C.

The distance from Fulbeck to Ganby is 10 miles.
The distance from Ganby to Horton is 18 miles.

Raksha is going to drive from Fulbeck to Ganby.
Then she will drive from Ganby to Horton.

Raksha leaves Fulbeck at 10 00
She drives from Fulbeck to Ganby at an average speed of 40 mph.

Raksha wants to get to Horton at 10 35

Work out the average speed Raksha must drive at from Ganby to Horton.

James and Peter cycled along the same 50km route.

James took hours to cycle the 50km.

Peter started to cycle 5 minutes after James started to cycle.
Peter caught up with James when they had both cycled 15 km.

James and Peter both cycled at constant speeds.

Work out Peter's speed.

Sean drives from Manchester to Gretna Green.

He drives at an average speed of 50 mph for the first 3 hours of his journey

He then has 150 miles to drive to get to Gretna Green.
Sean drives these 150 miles at an average speed of 30 mph.

Sean says,

"My average speed from Manchester to Gretna Green was 40 mph."

Is Sean right?
You must show how you get your answer.

In May 2019, the distance between Earth and Mars was 3.9 10⁷ km.

In May 2019, a signal was sent from Earth to Mars.
Assuming that the signal sent from Earth to Mars travelled at a speed of 3 10⁵ km per second,

how long did the signal take to get to Mars?

....................................seconds

The speed of the signal sent from Earth to Mars in May 2019 was actually less than 3 10⁵ km per second.

How will this affect your answer to part (a)?

A car travels at 108 km/h for 20 seconds.
 
Calculate the distance the car travels.
Give your answer in metres.
 

............................................ m

The diagram shows a solid triangular prism.

The prism is made from metal.
The density of the metal is 6.6 grams per cm³.

Calculate the mass of the prism.

A, B and C are 3 service stations on a motorway.

AB = 25 miles
BC = 25 miles

Aysha drives along the motorway from A to C.

Aysha drives at an average speed of 50 mph from A to B.
She drives at an average speed of 60 mph from B to C.

Work out the difference in the time Aysha takes to drive from A to B and the time Aysha takes to drive from B to C.
Give your answer in minutes.

A gold bar has a mass of 12.5 kg.

The density of gold is 19.3 g/cm³

Work out the volume of the gold bar.
Give your answer correct to 3 significant figures.

Tame Valley is a company that makes yoghurt.

A machine fills trays of 20 pots with yoghurt.
In one hour, the machine fills a total of 15 000 pots.

Work out how many seconds the machine takes to fill each tray of 20 pots.

There are 18500 gallons of fuel in a fuel tank.

The fuel is pumped from the fuel tank into a plane at a rate of 1700 litres per minute.

1 gallon = 4.5 litres.

How many minutes will it take to empty the fuel tank completely?
Give your answer to the nearest minute.

Change a speed of 50 metres per second to a speed in kilometres per hour.

.......................... kilometres per hour

A block of wood has a mass of .
The wood has density 

Work out the volume of the block of wood.
Give your answer correct to  significant figures.

Change a speed of  kilometres per hour to a speed in metres per second.