The Tools Used to Measure Density
Scale. Mass is one of the most easily obtained measurements. ...
Graduated Cylinder. The most accurate way to determine an object's volume, especially in the case of an irregularly shaped object, is to immerse it in water and measure the amount of water it displaces. ...
Calculating Density. ...
Hydrometer. ...
The Value of Density.
        
             
        
        
        
Answer:
a)-2m/s^2
b)27.2m/s
Explanation:
Hello! The first step to solve this problem is to find the mass of the block remembering that the definition of weight force is mass by gravity (g=9.8m / s ^ 2)
W=455N=weight
W=mg
W=455N=weight

The second step is to draw the free body diagram of the body (see attached image) and use Newton's second law that states that the sum of the forces is equal to mass by acceleration

for point b we use the equations of motion with constant acceleration to find the velocity

Where 
Vf = final speed
Vo = Initial speed
=0
A = acceleration
=2m/s
X = displacement
=6.8m
Solving

 
        
             
        
        
        
Gamma rays because it has more penetrating power and frequency but shorter wavelength.
        
             
        
        
        
I don't really know the answer but maybe north pole and south pole?