A motorcycle accelerates from a stop at a rate of 4m/s 2 for 20 seconds. It then continues at a
constant speed for 40 seconds. You may use the blank graph below to plot the speed vs. time
of the motorcycle. What is the motorcycle's speed at 45 seconds?

Respuesta :

After 20 s, the motorcycle attains a speed of

[tex]\left(4\dfrac{\rm m}{\mathrm s^2}\right)(20\,\mathrm s)=80\dfrac{\rm m}{\rm s}[/tex]

and it continues at this speed for the next 40 s. So at 45 s, its speed is 80 m/s.