The density of the material would be 
25/6 grams per cm^3.
to obtain the result above this is what we do:
density is calculated as: (the mass of the given material or object) / volume of the material 
which leads us to 50grams /12cm^3
 
        
             
        
        
        
Answer:

Explanation:
Assuming no energy lost, according to the law of conservation of energy, the kinetic energy of the automobile becomes potential energy after the crash:

Here m is the automobile's mass, v is the speed of the car before impact, k is the "bumper" constant and x is the compression of the bumper due to the collision. Solving for v:

 
        
             
        
        
        
Answer:
The final position of the ship after the given time period is  42 km West of B.
Explanation:
Given;
average velocity of the ship, v = 35 km/h
time taken for the ship to reach point D, t = 1.2 hours
The position of the ship after the given time period is calculated as follows;
x = v x t
x = (35 km/h) x 1.2 h = 42 km
x  = 42 km West of B.
Therefore, the final position of the ship after the given time period is  42 km West of B.
 
        
             
        
        
        
Answer:
c. is negative
Explanation:
When the magnitude of force is multiplied with the force vector's projection along the direction of the vector of displacement which is negative as it is a resistive force we get the work done. 
As the wind is acting in opposite direction of the force which is being applied by the plane the work done will be negative. Also, the net work will be the sum of many smaller negative quantities.
Hence, the answer here is negative.