(a) Determine at

t=4sec

, the pushrim-activated wheclehair controller output (

u

) if:\

t_(c)=5sec

\

t_(r)

is initialized to 0\ Threshold torque is

1Nm

\ Pushrim torque at release is

10Nm

\ The wheelchair is traveling at a speed that is less than the threshold velocity\ (b) What is the controller output when

t=0.5

and

t=6sec

?