An 8 g bullet leaves the muzzle of a rifle with
a speed of 611.9 m/s.
what constant force is exerted on the bullet
while it is traveling down the 0.8 m length of
the barrel of the rifle?
answer in units of n.

1872 N

Explanation:

This problem can be solved by using one of the Kinematics equations and Newton's second law of motion:

(1)

(2)

Where:

is the bullet's final speed (when it leaves the muzzle)

is the bullet's initial speed (at rest)

is the bullet's acceleration

is the distance traveled by the bullet before leaving the muzzle

is the force

is the mass of the bullet

Knowing this, let's begin by isolating from (1):

(3)

(4)

(5)

Substituting (5) in (2):

(6)

Finally:

a.metals can become magnetic if they have many spinning electrons that create magnetic fields.d.only some metals are attracted by magnets; these metals are called ferromagnetic.

d.wrapping an insulated wire around a metal with ferromagnetic properties and applying an electric current.

r = ρ x length / area  

ρ = r x area / length  

ρ is in ohm-meters  

in basic units, it is m³kg/s³a²  

i think this is it.