The position of a 50 g oscillating mass is given by x(t)=(2.0cm)cos(10t−π/4), where t is in s. If necessary, round your answers to three significant figures. Determine:
a) amplitude _____ cm
b) the period ______s
c) the spring constant _____ N/m
d) the phase constant ______ rad
e) the initial coordinate of the mass ______ cm
f) the initial velocity ________ cm/s
g) the maximum speed ________ cm/s
h) the total energy _________ mJ
i) the velocity at t=0.40 s __________ cm/s