Answer:
Work done = 13605.44
Explanation:
Data provided in the question:
For elongation of 2.1 cm (0.021 m) work done by the spring is 3.0 J
The relation between Energy (U) and the elongation (s) is given as:
U =
................(1)
where,
k is the spring constant
on substituting the valeus in the above equation, we get
3.0 = 
or
k = 13605.44 N/m
now
for the elongation x = 2.1 + 4.1 = 6.2 cm = 0.062 m
using the equation 1, we have
U = 
or
U = 26.149 J
Also,
Work done = change in energy
or
W = 26.149 - 3.0 = 23.149 J
Answer:
works out for only one week
Explanation:
In order to develop a good habit, there are certain things that you can do like:
-Develop a consistent schedule of exercise which allows you to work everyday over a period of time which helps you to create a routine that you would get used to it creating a habit.
-Work out with a friend which allows you to have someone to motivate you and that would go everyday with you which would help to be consistent.
-Use success strategies that are ways in which you can achieve your goal of creating a good habit to exercise.
According to this, the option that would not help Bob develop a good habit is if he works out for only one week as doing something everyday is what would help you to create the habit.
We use the formula,
.
Here, v is velocity and its value given 26 mi/h ( in m/s,
) and d is distance and its value is given 80 m.
Substituting these values in above formula we get,

Thus, the time delay between green lights on successive blocks to keep the traffic moving continuously is 6.88 s
Answer:
This is because normal force is exerted perpendicularly to the point of contact between the upper and lower objects.
Explanation:
This is because the upper object is still subject to gravitational pull. Therefore, the amount of force it exerts on the lower object due to gravity will be equal to the normal force that acts in the negative direction of gravitational force. Additionally, normal force is evident because the upper object will not go into the lower object.