Question

A remote controlled, battery operated toy car starts at t = 0 and travels 6.0 m at constant speed of 0.23 m/s. It now accelerates at 0.15m/s² for another 6.0m and then maintains a constant speed for another 6.0m. The care now slows at 0.10m/s² for 6.0m coming to a stop. How long did it take the car to travel the 24.0m?

Answer 1

During phase 1

t1= 6/0.23= 26.09 s

During phase 2

6= 0.23*t2+0.5*0.15* t2^2

Solving for t2,

t2= 7.541 s

During phase 3

V= at= 0.15*7.541= 1.13 m/s

t3= 6/1.13= 5.3 s

During phase 4

6= 1.13*t4-0.5*0.1*t4^2

Solving for t4,

t4= 8.527 s

Total time taken

T= 26.09+7.541+5.3+8.527= 47.485 s

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quadratic equation,

ax^2+ bx +c= 0

Value of x can be determined by the following formulation

x= -[b+sqrt(b^2-4*a*c) ]/(2*a)

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Comment in case any doubt.. good luck