Answer:
So mass of the object will be 3.2 kg
Explanation:
We have net force on the object F = 16 N
Acceleration of the object 
We have top find the mass of the object
From newton law of motion we know that force is given by
F = ma , here m is mass and a is acceleration
So 

So mass of the object will be 3.2 kg
Answer:
20 N/m
Explanation:
From the question,
The ball-point pen obays hook's law.
From hook's law,
F = ke............................ Equation 1
Where F = Force, k = spring constant, e = compression.
Make k the subject of the equation
k = F/e........................ Equation 2
Given: F = 0.1 N, e = 0.005 m.
Substitute these values into equation 2
k = 0.1/0.005
k = 20 N/m.
Hence the spring constant of the tiny spring is 20 N/m