In your job in a police lab, you must design an apparatus to measure the muzzle velocities of bullets fired from handguns. Your solution is to attach a 2.00 kgkg wood block that rests on a horizontal surface to a light horizontal spring. The other end of the spring is attached to a wall. Initially the spring is at its equilibrium length. A bullet is fired horizontally into the block and remains embedded in it. After the bullet strikes the block, the block compresses the spring a maximum distance dd. You have measured that the coefficient of kinetic friction between the block and the horizontal surface is 0.38. The table below lists some firearms that you will test. A grain is a unit of mass equal to 64.80 mgmg.
| Bullet ID | Type | Bullet Mass (grains) |
Muzzle Velocity (ft/sft/s) |
| A | .38Spec Glaser Blue | 80 | 1667 |
| B | .38 Spec Federal | 125 | 945 |
| C | .44Spec Remington | 240 | 851 |
| D | .44Spec Winchester | 200 | 819 |
| E | .45ACP Glaser Blue | 140 | 1355 |
a)You want the maximum compression of the spring to be 0.30 mm. What must be the force constant of the spring?
Express your answer with the appropriate units.