Question

lilian wonders how fast a train can move around a particular curve before it falls off of the track. which of the following is the best way for lillian to figure this out?
a. build a model train and track, and test one train going around several different curves at one speed.
b. build a model train and track, and test different - sized trains going around one curve at the same speed.
c. drive a train along a curve at different speeds until it falls off of the track.
d. build a model train and track, and test one train going around one curve at different speeds.

Explanation:

Lillian's question focuses on the maximum speed a train can take a specific curve before derailing. Option D isolates the variable of speed (testing different speeds) while keeping the train and curve constant, which directly addresses the question. Option A changes curves (not the focus), B changes train size (irrelevant), and C is unsafe and impractical for real trains. Thus, D is the best method.

Answer:

D. Build a model train and track, and test one train going around one curve at different speeds.