Question

A large fake cookie sliding on a horizontal surface isattached to one end of a horizontal spring with spring constantk = 425 N/m; the other end ofthe spring is fixed in place. The cookie has a kinetic energy of19.0 J as it passes through theposition where the spring is unstretched. As the cookie slides, africtional force of magnitude 10.0 N acts on it.

(a) How far will the cookie slide from the positionwhere the spring is unstretched before coming momentarily torest?
(b) What will be the kinetic energy of the cookie as it slides backthrough the position where the spring is unstretched?

Answer 1

Step-by-step explanation:

spring constant k = 425 N/m

a ) At the point of equilibrium

restoring force = frictional force

= kx = 10 N

425 x = 10

x = 2.35 cm

b )

Work done by frictional force

= -10 x 2.35 x 10⁻² x 2 J ( Distance is twice of 2.35 cm )

= - 0.47 J

= Kinetic energy remaining with the cookie as it slides back through the position where the spring is unstretched .

= 425 - 0.47

= 424.53 J

=