Given:
The mass of the sample is,

The volume is

To find:
The density
Explanation:
The volume is,

The density is,

Hence, the density is
 
 
        
             
        
        
        
We know that: 1 L = 100 cL. Or 1 cL = 0.01 L. Then we will make the conversion: 34.9 cL = 34.9 / 100 L = 0.349 L. Also: 1 hL = 100 L. 0.349 L = 0.349 / 100 hL = 0.00349 hL. This can be also written as: 3.49 * 10^(-3) hL ( in the scientific notation ). Answer: 3.49 cL = 0.00349 <span>hL </span>
        
             
        
        
        
Explanation:to find the area you must first find the radius given you have the diameter you cut the diameter in half giving you 40 then you follow the formula “A= (pie)r (squared) leaving you with 
answer:5024
        
             
        
        
        
A magnet has two poles that is called north and sound the only information I can give
        
             
        
        
        
Explanation:
Given Data
Total mass=93.5 kg
Rock mass=0.310 kg
Initially wagon speed=0.540 m/s
rock speed=16.5 m/s
To Find
The speed of the wagon 
Solution
As the wagon rolls, momentum is given as
P=mv
where 
m is mass
v is speed
put the values
P=93.5kg × 0.540 m/s
P =50.49 kg×m/s
Now we have to find the momentum of rock 
momentum of rock = mv
momentum of rock = (0.310kg)×(16.5 m/s)
momentum of rock =5.115 kg×m/s  
From the conservation of momentum we can find the wagons momentum So
wagon momentum=50.49 -5.115 = 45.375 kg×m/s  
Speed of wagon = wagon momentum/(total mass-rock mass)
Speed of wagon=45.375/(93.5-0.310) 
Speed of wagon= 0.487 m/s
Throwing rock backward,
momentum of wagon = 50.49+5.115 = 55.605  kg×m/s
Speed of wagon = wagon momentum/(total mass-rock mass)
speed of wagon = 55.605  kg×m/s/(93.5kg-0.310kg) 
speed of wagon= 0.5967 m/s