The mass in the following illustration is guided by the frictionless rail and has a mass of 40 kg. • The spring constant, , is 3000 N⁄m. • The spring is compressed sufficiently and released, such that

Problem 1 to 4 refer to the following situation.

• The mass in the following illustration is guided by the frictionless rail and has a mass of 40 kg.

• The spring constant, , is 3000 N⁄m.

• The spring is compressed sufficiently and released, such that the mass barely reaches at point .

 _____1. What is the initial spring compression?

a. 0.96 m b. 1.25 m c. 1.35 m

_____2. What is the kinetic energy of the mass at point ? a. 19.8 J b. 219 J c. 392 J

_____3. What is the velocity of the mass at point ?

a. 3.13 m⁄s b. 4.43 m⁄s c. 9.80 m⁄s

d. 1.80 m

d. 2350 J

d. 19.6 m⁄s _____4. What is the energy stored in the spring if the spring is compressed 0.5 m?

a. 375 J b. 750 J c. 1500 J d. 2100 J

Problem 5 and 6 refer to the following illustration.

• A 50 kg block is released down a curved, frictionless surface.

• The radius of the curve is 5 m.

_____5. What is the tangential velocity of the block at point ?

a. 6.52 m⁄s b. 9.22 m⁄s c. 42.5 m⁄s d. 85.0 m⁄s

_____6. What is the instantaneous acceleration in the direction of travel of the block ? a. 0 m⁄s2 b. 2.45 m⁄s2 c. 4.91 m⁄s2 d. 19.6 m⁄s2

_____7. Which of the following is a unit of energy?

a.ft2 −lbm b.ft2 −lbf c.ft−lbm d.ft−lbf