Forces & Motion: Distance, Speed & Time

The concorde was a supersonic jet joint-developed by France and Great Britain in 1976.

The concorde could fly between New York and London in only 2.55 hours. These two cities are at opposite sides of the Atlantic Ocean, 5567 kilometres away.

Calculate the maximum speed of the concorde.

Answer explanation

V = D/T

V = 5567km / 2.55 hours

V = 2179 km/h

The concorde was a supersonic jet joint-developed by France and Great Britain in 1976.

It had a maximum speed of 2179 km/h. If the distance between New York and London is 5567 km, how long would it take to travel between the two cities?

Answer explanation

T = D/V

T = 5567km / 2179km/h

T = 2.55 hours

The concorde was a supersonic jet joint-developed by France and Great Britain in 1976.

It had a maximum speed of 2179 km/h. If the concorde took 2.55 hours to travel between New York and London, calculate the distance between the two cities (in kilometres).

Answer explanation

D = V x T

D = 2179 km/h x 2.55 hours

D = 5567 km

Cheetahs are the fastest land animal on Earth. If a cheetah covered a distance of 400 metres in 14.705 seconds, calculate its speed.

Give your answer to one decimal place.

Answer explanation

V = D/T

V = 400 m / 14.705 s

V = 27.2 m/s

Cheetahs are the fastest land animal on Earth. However, they can only maintain their top speed of 27 m/s for a few seconds. Calculate how far a cheetah could run in 3 seconds.

Round your answer to the nearest whole number (zero decimal places).

Answer explanation

D = V x T

D = 27 m/s x 3 s

D = 81 m

Cheetahs are the fastest land animal on Earth. If a cheetah covered a distance of 400 metres in 14.705 seconds, calculate its speed in kilometres per hour.

Round your answer to the nearest whole number (zero decimal places).

Answer explanation

V = D/T

V = 400 m / 14.705 s

V = 27.2 m/s

To get this value in hours, we multiply by 60 to get it in minutes, and then again by 60 to get it in hours.

V = 97926 metres/hour. However, the question asks for kilometres so we divide by 1000 to get 97.926 km/h.

Then we round this to 98 km/h for our final answer.

Peregrine falcons are the fastest animals on Earth, with a maximum dive speed of 389 km/h. They also like to nest on top of buildings.

Assuming they could accelerate to their top speed instantly, how many seconds would it take for a falcon nested on top of the burj khalifa (830 metres tall) to reach the ground?

Give your answer to two decimal places.

Answer explanation

The question gives the falcons speed as 390 km/h, we need it in m/s.

Easiest step is to convert km into metres by multiplying by 1000 to give 390,000 m/h.

There are 60 mins in an hour, so we divide this by 60 to get its speed per minute. Divide by 60 again to get the speed in m/s as 108.05 m/s.

The distance (height) is 830 m, so we do D/V = 830 m/108.05 m/s = 7.68 s

Peregrine falcons are the fastest animals on Earth, with a maximum dive speed of 389 km/h. They also like to nest on buildings.

Assuming they could accelerate to their top speed instantly, if a falcon had nested on the

burj khalifa and took 6.5 seconds to reach the ground, how high up had the falcon nested?

Give your answer to 1 decimal place.

Answer explanation

The question gives the falcons speed as 390 km/h, we need it in m/s.

Easiest step is to convert km into metres by multiplying by 1000 to give 390,000 m/h.

There are 60 mins in an hour, so we divide this by 60 to get its speed per minute. Divide by 60 again to get the speed in m/s as 108.05 m/s.

The falcon took 6.5 s for the flight and can fly at 108.05 m/s, so our sum is D = VxT, 108.05 m/s x 6.5 s = 702.3 metres

Peregrine falcons are the fastest animals on Earth. They also like to nest on buildings.

Assuming they could accelerate to their top speed instantly, if a falcon had nested on top of the

burj khalifa (830 metres above ground) it and took 7.68 seconds to reach the ground, determine the falcons top speed.

Give your answer to 1 decimal place.

Answer explanation

V = D/T

V = 830 m / 7.68 s

V = 108.1 m/s

If light travels at a speed of 3x10⁸ ms^-1, and the circumference of the Earth is 40,075 km, calculate the time it takes light to travel once around the Earth.

Give your answer to two decimal places.

Answer explanation

T = D/V

T = 40,075,000 metres! / 300,000,000 m/s

(Must have same units for this to work, can't use metres for one and kilometres for the other)

T = 0.13 seconds