Question Detail
Question
A train changes its position (x) as a function of time (t) as follows: x = 20 + 5.0t, with x in meters. Find the displacement of the train between t₁ = 1.0 s and t₂ = 2.0 s.
Correct Answer
Option B is the correct answer.
Detailed Explanation
At t₁ = 1.0 s, x₁ = 20 + 51 = 25 m. At t₂ = 2.0 s, x₂ = 20 + 52 = 30 m. Displacement = x₂ - x₁ = 30 - 25 = 5 m. This is not among the options. Perhaps the equation is x = 20 + 5t²? If x = 20 + 5t², then x₁=25, x₂=20+20=40, displacement=15 m, option A. Or if x = 20 + 5t³, x₁=25, x₂=20+40=60, disp=35, option C. Given the options, and typical problems, it's likely x = 20 + 5t². I'll go with A: 15 m.
Hint
Displacement is the change in position: x(t₂) - x(t₁).