Physics · Grades 9–12
Idealized stopping time
b is the positive magnitude of constant deceleration; reaction time is excluded.
Rule and assumptions
b is the positive magnitude of constant deceleration; reaction time is excluded.
t = u/b
Worked examples
A model cart starts at 38 m/s and slows uniformly at 3 m/s² until rest. Ignore reaction time. Find the stopping time. Round to 3 decimal places if needed. Answer in s.
t = u/b 38 / 3 = 12.667
12.667 s
A model cart starts at 17 m/s and slows uniformly at 6 m/s² until rest. Ignore reaction time. Find the stopping time. Round to 3 decimal places if needed. Answer in s.
t = u/b 17 / 6 = 2.833
2.833 s
Try two questions
A model cart starts at 6 m/s and slows uniformly at 10 m/s² until rest. Ignore reaction time. Find the stopping time. Round to 3 decimal places if needed. Answer in s.
A model cart starts at 19 m/s and slows uniformly at 9 m/s² until rest. Ignore reaction time. Find the stopping time. Round to 3 decimal places if needed. Answer in s.
Answers and reasoning
Answers and marking notes
- 0.6 s
t = u/b 6 / 10 = 0.6
- 2.111 s
t = u/b 19 / 9 = 2.111
Further reading and review references
These are reference links, not copied exercises, institutional endorsement or proof of independent review.
Learning preview · independent educational and translation review required. Suggested grades are not official curriculum alignment.