Hey there,
Density = Mass/Valume
D= 3.1/0.35
D= 8.86 g/cm3
Answer:

Explanation:
From the question we are told that:
Bowling ball Speed 
Beach ball Speed 
Let The Mass be equal i.e

Therefore
Generally the equation for Velocity of beach ball after collision
is mathematically given by
Since Velocity is Vector Quantity
Therefore



The complete sentence is:
A calorimeter directly measures changes in temperature in order to calculate specific heat.
In fact, the amount of energy acquired/released by a substance is directly proportional to its change in temperature due to the equation

where Q is the amount of energy, m is the mass of the substance, Cs is the specific heat of the substance and
is the change in temperature. Therefore, by knowing Q, m and by measuring the change in temperature, it is possible to calculate Cs, the specific heat capacity of the substance.