A car travels from point A to point B in a straight line.
At first, it moves at a speed of 70 km/h for half an hour.
Then, its speed is 85 km/h for 15 minutes.
What is the distance between points A and B?
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A car travels from point A to point B in a straight line.
At first, it moves at a speed of 70 km/h for half an hour.
Then, its speed is 85 km/h for 15 minutes.
What is the distance between points A and B?
To answer such questions, we need to know the rule for distance calculations:
Time * Speed = Distance
Using this formula, we can find the distance between the two points.
Let's first look at the first part, we know we traveled for half an hour at a speed of 70 km/h,
so we can substitute:
70*0.5=
and we'll find that the answer is 35
Let's continue to the second part of the route,
traveling for a quarter of an hour (need to remember that a quarter hour is 15/60) at a speed of 85 km/h, let's substitute:
15/60*85=
and we'll find that the answer is 21.25
Now all that's left for us is to combine the two routes - 21.25+35=56.25
km
David runs at a speed of 5 meters per second and covers a distance of 700 meters.
For how long does David run?
Because speed is given in km/h (kilometers per hour), time must also be in hours. If you use minutes directly, you'll get the wrong units and wrong answer!
Divide minutes by 60. For example: hours, or hours. Think of it as what fraction of an hour it represents.
Yes! Convert speeds to km/min first: 70 km/h = 70/60 km/min. Then multiply by minutes directly. But converting to hours is usually easier with these units.
The problem states the car travels in a straight line from A to B. So we simply add the distances from each segment. If direction changed, we'd need to consider displacement vs. distance.
Look at the speeds and times: traveling at 70-85 km/h for less than an hour should give a distance much less than 100 km. Our answer of 56.25 km fits this expectation perfectly!
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