Answer : The specific heat capacity of the alloy 
Explanation :
In this problem we assumed that heat given by the hot body is equal to the heat taken by the cold body.


where,
= specific heat of alloy = ?
= specific heat of water = 
= mass of alloy = 21.6 g
= mass of water = 50.0 g
= final temperature of system = 
= initial temperature of alloy = 
= initial temperature of water = 
Now put all the given values in the above formula, we get


Therefore, the specific heat capacity of the alloy 
C.) Laser. the light from the laser reflects off the shiny surface as the CD rotates
Explanation:
Calculate position vectors in a multidimensional displacement problem. Solve for the displacement in two or three dimensions. Calculate the velocity vector