The mass on the spring is 0.86 kg
Explanation:
The period of a mass-spring system is given by the equation

where
m is the mass
k is the spring constant
In this problem, we have:
k = 88.7 N/m is the spring constant
The system makes 15 oscillations in 9.24 s: therefore, the period of the system is

Now we can re-arrange the first equation to solve for the mass:

Learn more about period:
brainly.com/question/5438962
#LearnwithBrainly
Answer: The correct answer for the blank is- a. change its position relative to other objects.
Perception of motion can be described as a phenomenon of inferring the direction and speed and of objects, which are moving in a visual scene.
An object is said to be in motion if its position is changed with respect to objects that are present in its surrounding.
Thus, in order to sense motion of objects, humans beings are required to see an object change its position with respect to other objects.
Answer:
strontium has 50 neutrons