A block of mass 493 g is pushed against the

spring (located on the left-hand side of the

track) and compresses the spring a distance

4.9 cm from its equilibrium position (as shown

in the figure below). The block starts from

rest, is accelerated by the compressed spring,

and slides across a frictionless horizontal track

(as shown in the figure below). It leaves the

track horizontally, flies through the air, and

subsequently strikes the ground.

The acceleration of gravity is 9.81 m/s^2

a. what is the spring constant

b. what is the speed v of the block when it leaves the track?

c. what is the total speed of the block when it hits the ground?