Sure! Here's an AP Physics 2 exam question about nuclear reactions:

Question:

A certain nuclear reaction occurs with a given mass defect of 0.003 kg. If the reaction produces 2.5 x 10^14 J of energy, what is the total change in mass during the reaction?

Answer:

Given: Mass defect (Δm) = 0.003 kg Energy produced (E) = 2.5 x 10^14 J Speed of light (c) = 3.0 x 10^8 m/s

We can use Einstein's mass-energy equivalence equation to calculate the total change in mass:

ΔE = Δmc^2

Where: ΔE = change in energy Δm = change in mass c = speed of light

First, we need to rearrange the equation to solve for Δm: Δm = ΔE / c^2

Now, we can plug in the given values to find the change in mass: Δm = (2.5 x 10^14 J) / (3.0 x 10^8 m/s)^2 Δm = 2.78 x 10^-9 kg

Therefore, the total change in mass during the reaction is 2.78 x 10^-9 kg.

This demonstrates the application of the mass-energy equivalence principle and how to calculate the change in mass during a nuclear reaction.