A student pushed a box 32.0 m across a smooth, horizontal floor using a constant force of 124 N. If the force was applied for 8.
2 answers:
The power developed is 500 W ( to the nearest Watt)
Power(P) is the rate at which work is done. Work done (W) is the product of the force applied on the object and the displacement (s) made by the point of application of the force.
Therefore,
Substitute the given values of force , displacement and time
Thus the Power can be rounded off to the nearest value of 500 W
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:
It is given that the height of the tower is
The uncertainty the measurement of this height is
Drop time is measured as:
The uncertainty in measurement of time is:
Using the equation of motion: where,
is the distance covered,
is the initial velocity,
is the acceleration and
is the time.
(because canon ball is in free fall). we need to calculate the value of a=g.
The uncertainty in this value is given by:
Substitute the values: