Explanation:
Mass of bullet, m = 11.0 g = 0.011 kg
Initial speed of bullet, u = 210 m/s
Final speed of bullet, v = 0 m/s
Displacement of bullet, s = 22.6 cm = 0.226 m
We have equation of motion v² = u² + 2as
Substituting
0² = 210² + 2 x a x 0.226
a = -97566.37 m/s²
We have
Force, F = Mass x Acceleration
F = 0.011 x -97566.37 = -1073.23 N
Negative means opposite to the direction of motion of bullet.
Stopping force on the bullet is 1073.23 N to the left.