A student leaving school travels 100 m East before he realizes he left his textbook in his locker. He heads back towards school,
1 answer:
You might be interested in
Answer:
a = 9.81[m/s^2]; v = 18683.5[m/s]
Explanation:
The stament of the problem is:
Suppose that the man pictured on the front side is orbiting the earth (mass = 5.98 x 1024kg) at a distance of 310 miles (1600 meters = 1 mile) above the surface of the earth (radius = 4000 miles).
a. What acceleration does he experience due to the earth's pull?
b. What tangential velocity must he possess in order that he orbit safely (in m/s)?
First we need to convert all the initial data to units of the SI
Rs = 310 [mil] = 498897 [m]
RT= 400 [mil] = 643738 [m]
r = Rs + RT = 1142635 [m] "distance from the center of the earth to the man"
G = universal gravitational constant
M = mass of the earth [kg]
m = mass of the man [kg]
r = distance from the center of the earth to the man [m]
a)
The acceleration he is experimenting is the same acceleration given by the gravity, therefore:
a = g = 9.81[m/s^2]
b)
To find the tangential velocity, we must determinate the force exerted by the earth.
Now we will find the force exerted by the gravity when the man is orbiting the earth at distance r.
And this force will be equal to the following expression:
Given :
An object with weight 20 N was lifted to 0.5 meters.
To Find :
How high must you lift a 25 Newton book for it to have the same increase in potential energy as the given book.
Solution :
Since both have same potential energy :
Putting all given values in above equation :
Therefore, book with same potential energy is at a height of 0.4 m.