An aeroplane leaves an airport and flies due north at a speed of 1000km per hour. At the same time, another aeroplane leaves the same airport and flies due west at a speed of 1200 km per hour. How far apart will be the two planes after `1 1/2` hours ?

Find the time required to cover a distance of 250 km at a speed of 20km per hour.

In each of the following problems, clearly state what the relevant and irrelevant factors are while going through Steps 1, 2 and 4 given in this chapter :- Suppose a car starts from a place A and travels at a speed of 40 km/h towards another place B. At the same instance, another car starts from B and travels towards A at a speed of 30 km/h. If the distance between A and B is 100 km, after how much time will the cars meet?

Two cars start together in the same direction at the same place.The first goes with the speed of 10km/hr. The second goes at the speed of 8 km/hr in the first hour and increases the speed by 1/2 km each succeeding hour. After how many hours will the second car overtake the first if both cars go non-stop ?

The wheels of a car are of diameter 80 cm each. How many complete revolutions does each wheel make in 10 minutes when the car is travelling at a speed of 66 km per hour ?

Water flows in a tank 200mxx150m at the base, through a pipe whose cross section is 2 dm by 1.5 dm at the speed of 15 km per hour in what time, will the water by 3 metres deep?

A car travels 20 km in 1 hour and another 40 km in 3 hour. What is the average speed of the car?

An aeroplane is in level flight at 144 km per hour at an altitude of 1000m. How far from a given targets should it release a bomb sa as to hit the target?

Form the pair of linear equations In the following problems and find their solutions (if they exist) by any algebraic method. :- Places A and B are 100 km apart on a highway. One car starts from A and another from B at the same time. If the cars travel in the same direction at different speeds they meet in 5 hours. If they travel towards each other, they meet in 1 hour. What are the speeds of the two cars ?