A glider on an air track moves in the +x direction with a constant acceleration.

Question

A glider on an air track moves in the +x direction with a constant acceleration. It has two flags, each exactly 25.4 mm long, with the midpoints of the flags separated by 162 mm. The first flag interrupts the photogate timer for a time 50 ms, and the second flag interrupts the photogate timer for a time 45 ms.

1) What was the average velocity of the glider when the first flag was interrupted?

2) What was the average velocity of the glider when the second flag was interrupted?

3) Approximately how much time elapsed between the passage of the first flag and the passage of the second flag?

4) Calculate the approximate acceleration of the glider.

Explanation / Answer

A glider on an air track moves in the +X direction with a constant acceleration. It has two flags, each exactly 25.4 mm long, with the midpoints of the flags separated by 162 mm. The first flag interrupts the photogate timer for a time 50 ms, and the second flag interrupts the photogate timer for a time 45 ms. You can use the time it takes to interrupt a flag to get an approximate value of instantaneous velocity at that time; Initial velocity = V(o) = 25.4/50 = .508 mm/ms final velocity = V = 25.4/45 = .564 mm/ms Between those velocities the cart moves 162 mm. So use kinematic eq to get accel. a = (V^2 - V(o)^2)/2x = (.318 - .258)/(2)(162) = .000185 mm/msms Then use another kinematics eq to get the elapsed time; t = (V - V(o))/a = (.564 - .508)/.000185 = 302.7 ms = .3 sec.

Related Questions

Navigate

• Browse (All)
• Browse A
• Subjects

---

---

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.