Derive a general expression for the speed v of the car. Make sure that your expr

Question

Derive a general expression for the speed v of the car. Make sure that your expression would give the correct value for the speed (in m/s), but you don't need to put in anything explicitly about units (unlike what you see in the original expression for r ).

A Wild Ride Part A A car in a roller coaster moves along a track that consists of a sequence of ups and downs. Let the x axis be parallel to the ground and the positive y axis point upward. In the time interval from t 0 to t = 4 s, the trajectory of the car along a certain section of the track is given by At t 2.0 s is the roller coaster car ascending or descending? Hints ascending FA(1 m/s)ti A (1 m/s)t - 6(1 m/s2)t2]3 descending where A is a positive dimensionless constant. Submit My Answers Give Up Correct Part B Derive a general expression for the speed v of the car. Make sure that your expression would give the correct value for the speed (in m/s), but you don't need to put in anything explicitly about units (unlike what you see in the original expression for T). Express your answer in meters per second in terms of A and t Hints A + (3At2-12.4t) m/s u= Submit My Answers Give Up Incorrect; Try Again; 3 attempts remaining

Explanation / Answer

r = A*[t i + (t^3 - 6t^2) j]

v = dr/dt

v = A*d[t i + (t^3 - 6t^2) j]/dt

v = A*[1 i + (3t^2 - 12t) j]

|v| = sqrt (vx^2 + vy^2)

|v| = sqrt (A^2 + (3At^2 - 12At)^2)

Related Questions

Navigate

• Browse (All)
• Browse D
• Subjects

---

---

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