Show your work! An 800kg cannon expels a cannonball. If, after the explosion, the cannon is moving to the LEFT with a velocity of 4 m/s, and cannon ball is fired at a rate of 30 m/s to the RIGHT. What is the mass of the cannon ball?

106,67 kg

Explanation:

momentum before = momentum after

p before = p after

momentum = p = m v

m = mass

v = velocity

v = + = to the right

v = - = to the left

vo = the velocity of both cannon and cannon ball before fire

p before = p after

(mass cannon (mc) + mass cannon ball (mcb)) x vo = mc x vc + mcb x vcb

(800 + mcb) x 0 = 800 x (-4) + mcb x 30

0 = -3200 + 30mcb

3200 = 30 mcb

mcb = 3200/30 = 106,67 kg

pythagoras' theorem

square root (-5^2+9^2)

square root (25+81)

square root (106)

angle is tan^-1(9/5)

neg x, pos y