The U. S.S. Constitution, the oldest fully commissioned war ship in the world, is docked in Boston, Massachusetts. Also known as “Old Ironsides” for her
seemingly impenetrable hull, the frigate houses 56 pieces of heavy artillery.
Mounted on bearings that allow them to recoil at a speed of 1.30 m/s are
20 carronades, each with a mass of 1000. kg. If a carronade fires a 14.5-kg
cannonball straight ahead, with what muzzle velocity does the cannonball
leave the cannon?

Yup no bull frogs here man

Answer: a charge of -1.0  × 10⁻⁴ c must be placed  at x = 26 m.the sign of the charge will be the same sign as the  -4.0  µc charge.======electricstatic force between two point charges  is given by    where k is coulomb's constant,  8.99×10⁹  n·m²/c², q₁ and q₂ are the point charges, and r is the distance between the two point charges.assign positive to q₁let q₁ =  6.0 µc, q₂ = -4.0  µc, q₀ represent the charge at the origin, and q₃ represent this new charge to place.the charge at the origin q₀ would experience the following force f₀₁ from q₁, with r = 6.0 m (note that 1  µc = 10⁻⁶ c)    the force from q₂    the force from q₃    the net force on the origin charge, q₀, has to be zero for no electrostatic forcehaving an equation where k and q₀ can be divided out of the equation will allow us to solve for q₃    isolating:     a charge of -1.0  × 10⁻⁴ c must be placed  at x = 26 m.the sign of the charge will be the same as the  -4.0  µc charge

The answer is d, you can easily test a theory! hope i you : )