# Speed question?

You’ve been kidnapped by chemists and driven away. Their blindfold isn’t working very well so you can see the speedometer that says 30km/h. You estimate that you’ve been driving for about 30 minutes now. How far have they taken you?

• Andrew Smith
5 days ago

They cannot have kidnapped you and driven in town. Every traffic light causes them to slow down so there is no way that they would average the speed shown on the speedo.

In Beijing the answer would be half an hour-> about 200 m along the traffic jam ( on a good day ).

However if you wish to apply the physics

Speed = distance / time

distance = speed * time = 30 km/hr * 1/2 hr -> 15 km max.

Now actually they drove around the block several times and you are now in the basement of the house next door to your own.

The chemists are working in a drug lab there and were afraid that you had heard their activities.

By kidnapping you and doing this they intend to release you later.

You will conclude that they are a long way from your home and be unable to assist the police in their investigations.

“A little knowledge is a dangerous thing”

• Anonymous
5 days ago

Just think carefully because this is only an age 10-11 question.

That means if you travel for 1 hour, the distance you cover will be 30km.

But you are only travelling for half this time (30mins = half an hour).

So you will only cover half of 30km, which is 15km.

• spot a
5 days ago

30 km/h for 30 min = 15km

If they drove at this speed in a large circle they took you 15 km in total but your vector distance is zero

• johnboiii
5 days ago

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• Steve
5 days ago

For the answer ’15 km’ to be correct, you have to assume the traveling has been in a straight line. Depending on the actual path taken, the answer could be between 0 & 15km.

• oubaas
5 days ago

stretched distance = 30*0.5 = 15.0 km

displacement : whichever in the range 0÷15 km

• gsr
5 days ago

If the blindfold was not working very well, I would be trying to figure out if they had weapons, and then how to get away. I wouldn’t be thinking about physics problems.

• cellular
5 days ago

consider no traffic jam just straight forward physics,

d=v/t

d=30/0.5= 15 km

hope that helps.

• Anonymous
5 days ago

If you can tell me if the speed 30km/h is constant i can calculate it

• tom7railway
5 days ago

They haven’t really kidnapped you, they’re just looking for a reaction.