A bird flies from the South Pole to the North Pole. Part of the journey is 1000 miles that takes 2 weeks. What is the bird’s vel
2 answers:
The correct answer to the question is : 2.976 miles/hour.
CALCULATION:
As per the question, the distance travelled by the bird X = 1000 miles.
The time taken by the bird to cover that distance t = 2 weeks.
= 2 × 7× 24 hours
= 336 hours
We are asked to calculate the speed of the bird.
The speed of the bird is calculated as -
speed v =
=
= 2.976 miles/hour [ans]
Hence, the velocity of the bird is 2.976 miles/hour.
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Answer:
We have to show surface area ,with few conditions that is by considering Force
and Pressure
to be respectively.
Explanation:
The atmospheric pressure is on Earth's surface.
The magnitude of the force exerted on a person by the atmosphere is .
Now to calculate surface area we can find it from and re-arranging it to.
So plugging the values,
Surface area
Hence from the above calculations we can say that surface area is .
So the surface area of an average person can be said to have , using the concept of pressure and force.
In order to accelerate the dragster at a speed 
, its engine must do a work equal to the increase in kinetic energy of the dragster. Since it starts from rest, the initial kinetic energy is zero, so the work done by the engine to accelerate the dragster to 100 m/s is
however, we must take into account also the fact that there is a frictional force doing work against the dragster, and the work done by the frictional force is:
and the sign is negative because the frictional force acts against the direction of motion of the dragster.
This means that the total work done by the dragster engine is equal to the work done to accelerate the dragster plus the energy lost because of the frictional force, which is
:
So, the power delivered by the engine is the total work divided by the time, t=7.30 s:
And since 1 horsepower is equal to 746 W, we can rewrite the power as
however, we must take into account also the fact that there is a frictional force doing work against the dragster, and the work done by the frictional force is:
and the sign is negative because the frictional force acts against the direction of motion of the dragster.
This means that the total work done by the dragster engine is equal to the work done to accelerate the dragster plus the energy lost because of the frictional force, which is
So, the power delivered by the engine is the total work divided by the time, t=7.30 s:
And since 1 horsepower is equal to 746 W, we can rewrite the power as