Answer:
My answer is 7.2 km
Explanation:
When Stephen goes to the south and then to the east, he is drawing a right triangle, where the 4 km and 6 km sides are the cathetus of a right triangle.
Then we use the Pithagorean theorem to solve this problem. We need to find the hypotenuse.
c² = a² + b²
c² = 4² + 6²
c² = 16 + 36
c² = 52
c = 7.2 km
Work = force x distance
You can see time doesn’t matter (if we were talking about power, which is the RATE at which work is performed, that would be a different story).
W = 2 x 5 = 10 foot-pounds of work
Foot-pounds are gross units. Better to work in SI units when you can!
Answer:
mph
Explanation:
= Speed of bird in still air
= Speed of wind = 44 mph
Consider the motion of the bird with the wind
= distance traveled with the wind = 9292 mi
= time taken to travel the distance with wind
Time taken to travel the distance with wind is given as
eq-1
Consider the motion of the bird with the wind
= distance traveled against the wind = 6060 mi
= time taken to travel the distance against wind
Time taken to travel the distance against wind is given as
eq-2
As per the question,
Time taken with the wind = Time taken against the wind
mph
<span>The tire will rotate about 10 million times.
An automobile tire is slightly less than 2 and half feet in diameter. It's circumference is that times pi with is a bit over 3. So 2.5 * 3 = 7.5 ft as an estimate for how far the tire rolls per revolution.
A mile is a bit over 5000 feet, so call it 700 revolutions per mile.
For the 35000 miles, call it 7 times 5000 miles. Now 7 times 7 is a bit under 50, so call 7 * 700 = 5000. And 5000 times 5000 = 25000000. The nearest order of magnitude is 10 million.
So as an order of magnitude estimate, a automobile tire will rotate about 10 million times during it's life.</span>
