Im going to guess on this one, and say that it is chemical.
What are the options for A,B,C,D? There’s arrows
The student can measure a liquid's volume by using a graduated cylinder, or a beaker. Mass can be measured by first weighing an empty container on a scale, and then by adding the liquid to the container and weighing it again.
Silicon is used in the manufacturing of microchips and is also used in motherboards. We use it in our daily lives. It is a high tech element.
Use the conservation of angular momentum; angular momentum at the beginning = angular momentum at the end
Conservation of angular momentum:
I1 w1 = I2 w2
Where I is the moment of inertia. For a sphere, I=2/5 m R^2. Substituting into the equation above we get
w2 = I1 w1 / I2 = w1 m1 R1^2 / (m2 R2^2)
w2 = w1 4 * (R1/R2)^2
= 4*(1)*(7E5/7.5)^2
= 3.48E10 revs/(17days)
= 2.04705882 x 10^9 revs/sec