79. Since T = 0.500 s, we note that ω = 2π/T = 4π rad/s. We work with SI units, so m = 0.0500 kg and

v

m

= 0.150 m/s.

(a)Since ω =

k/m, the spring constant is

k = ω

2

m = (4π)

2

(0.0500)= 7.90 N/m .

(b)We use the relation v

m

= x

m

ω and obtain

x

m

=

v

m

ω

=

0.150

4π

= 0.0119 m .

(c)The frequency is f = ω/2π = 2.00 Hz (which is equivalent to f = 1/T ).