It would be a high pitched sound. Hope this helps.
Force exerted by the bullet = mass * acceleration = 0.013 * 850 = 11.05 Newtons.
the rifle exerts same force in opposite direction so we have
11.05 = 3.5 * a
acceleration = 11.05 / 3.5 = 3.16 m /s^-2
Using the formula KE=1/2mv^2
a: The kinetic energy doubles.
b: The kinetic energy quadruples.
c: The kinetic energy is cut in half.
Hopefully it’s clear how the formula can show you this.
If it starts at rest the initial velocity is 0.
For an acceleration, a, and time, t, the velocity is v=at. Since at t=4, v=7, then a=7/4=1.75m/s^2
