You have a light spring which obeys Hooke's law. This spring stretches 2.92 cm vertically when a 2.70 kg object is suspended fro
1 answer:
(a) 907.5 N/m
The force applied to the spring is equal to the weight of the object suspended on it, so:
The spring obeys Hook's law:
where k is the spring constant and is the stretching of the spring. Since we know
, we can re-arrange the equation to find the spring constant:
(b) 1.45 cm
In this second case, the force applied to the spring will be different, since the weight of the new object is different:
So, by applying Hook's law again, we can find the new stretching of the spring (using the value of the spring constant that we found in the previous part):
(c) 3.5 J
The amount of work that must be done to stretch the string by a distance is equal to the elastic potential energy stored by the spring, given by:
Substituting k=907.5 N/m and , we find the amount of work that must be done:
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The image is missing (however it's not necessary to solve the problem).
The correct answer is A) decreases, because the gravitational force is inversely proportional to the square of the distance. In fact, the magnitude of the gravitational force between two object of mass M and m, at a distance d one from each other, is
where G is the gravitational constant. As can be seen from the formula, if the distance d between the two object increases, the intensity of the force decreases.
The correct answer is A) decreases, because the gravitational force is inversely proportional to the square of the distance. In fact, the magnitude of the gravitational force between two object of mass M and m, at a distance d one from each other, is
where G is the gravitational constant. As can be seen from the formula, if the distance d between the two object increases, the intensity of the force decreases.
Answer:
For this case, if we try to find the final temperature of A and B, we see that we will obtain an expression in terms of specific heats and masses, from the information given we know the relationship between specific heats, but we don't know the relationship that exists among the masses, then the best option for this case is:
d) More information is needed
(The relation between the masses is not given)
Explanation:
For this case we know the following info:
Where c means specific heat for the substance A and B.
We also know that the initial temperatures for both sustances are equal:
We assume that we don't have melting or vaporization in the 2 substances. So we just have presence of sensible heat given by this formula:
And for this case we know that Both A and B are at the same initial temperature when equal amounts of energy are added to them, so then we have this:
And if we replace the formula for sensible heat we got:
And if we replace for the change of the temperature we got:
And since we have this:
For this case, if we try to find the final temperature of A and B, we see that we will obtain an expression in terms of specific heats and masses, from the information given we know the relationship between specific heats, but we don't know the relationship that exists among the masses, then the best option for this case is:
d) More information is needed
(The relation between the masses is not given)