SAT Subject Physics Practice Question 60: Answer and Explanation
7. A block of mass m = 4 kg on a frictionless, horizontal table is attached to one end of a spring of force constant k = 400 N/m and undergoes simple harmonic oscillations about its equilibrium position (x = 0) with amplitude A = 6 cm. If the block is at x = 6 cm at time t = 0, then which of the following equations (with x in centimeters and t in seconds) gives the block’s position as a function of time?
A. x = 6 sin(10t + π)
B. x = 6 sin(10πt)
C. x = 6 sin(10πt – π)
D. x = 6 sin(10t)
E. x = 6 sin(10t –π)
Correct Answer: A
The only equation that gives x = 6 when t = 0 is the one in A.