Hello!
A stretched spring has 5184 J of elastic potential energy and a spring constant of 16,200 N/m. What is the displacement of the spring ?
Data:



For a spring (or an elastic), the elastic potential energy is calculated by the following expression:

Where k represents the elastic constant of the spring (or elastic) and x the deformation or displacement suffered by the spring.
Solving:









Answer:
The displacement of the spring = 0.8 m
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I Hope this helps, greetings ... Dexteright02! =)
Mass of the object m = 2.9 kg
Force F1 = 28.449 N
F1 = m1 x a => a = F / m => 28.449 / 2.9 => a = 9.81, which is gravitational acceleration.
In the same lab, a = g = 9.81, second object F2 = 48.7N = m2 x a
m2 = F2 / a => 48.7 / 9.81 => m2 = 4.96 kg
Mass of the second object m2 = 4.96 kg
Answer:
Work done by the frictional force is 
Explanation:
It is given that,
Mass of the car, m = 1000 kg
Initial velocity of car, u = 26.1 m/s
Finally, it comes to rest, v = 0
We have to find the work done by the frictional forces. Work done is equal to the change in kinetic energy as per work - energy theorem i.e.



W = −340605 J
or

Hence, the correct option is (a).