Question

which of the following might a physicist choose to study?
a. the amount of salt in human saliva
b. the effects of water pollution on tadpoles
c. the effects of fast pitches on wooden baseball bats
d. the amount of iron in moon rocks

Explanation:

A physicist studies matter, energy, and their interactions. Analyzing the amount of iron in moon rocks (matter composition) falls within physics. Option A (saliva salt) is more related to biology/biochemistry. Option B (water pollution on tadpoles) is environmental science/biology. Option C (fast pitches on bats) is more about materials science/engineering (though physics concepts are involved, but the focus here is more on the interaction in a sports - material context which is less core physics compared to analyzing moon rock composition).

Answer:

D. The amount of iron in moon rocks