Anything that is possibly solid or can be contained in a solid
Mass is the amount of matter that is contained in a certain object.
Like
20 kg
10 g
100 lb
Answer:
Acceleration due to gravity will be 
Explanation:
We have given length of pendulum l = 55 cm = 0.55 m
It is given that pendulum completed 100 swings in 145 sec
So time taken by pendulum for 1 swing 
We have to find the acceleration due to gravity at that point
We know that time period of pendulum;um is given by

So 

Squaring both side


So acceleration due to gravity will be 
Answer:
The impulse transferred to the nail is 0.01 kg*m/s.
Explanation:
The impulse (J) transferred to the nail can be found using the following equation:

Where:
: is the final momentum
: is the initial momentum
The initial momentum is given by:

Where 1 is for the hammer and 2 is for the nail.
Since the hammer is moving down (in the negative direction):
And because the nail is not moving:

Now, the final momentum can be found taking into account that the hammer remains in contact with the nail during and after the blow:
Since the hammer and the nail are moving in the negative direction:
=
= -9.7 m/s
Finally, the impulse is:

Therefore, the impulse transferred to the nail is 0.01 kg*m/s.
I hope it helps you!
Your answer is correct: Resident 4 would provide the scientist with the most valid results.