Answer
given,
x(t) = A t + B t²
A = -4.1 m/s
B = 5.4 m/s²
a) velocity of the particle is equal to the differentiation of Position w.r.t. time
[tex]\dfrac{dx}{dt}=\dfrac{d}{dt}(-4.1 t + 5.4 t^2)[/tex]
[tex]v =-4.1 + 2\times 5.4 t[/tex]
[tex]v = -4.1 + 10.8 t[/tex]
the above equation gives the function of velocity.
b) time at which velocity of particle is zero
v = -4.1 + 10.8 t
inserting v = 0 and calculating v
0 = -4.1 + 10.8 t
10.8 t = 4.1
t = 0.38 s
time at which velocity is zero is equal to 0.38 s.