Nate the skate was an avid physics student whose main non‑physics interest in life was high‑speed skateboarding. in particular, nate would often don a protective suit of bounce-tex, which he invented, and after working up a high speed on his skateboard, would collide with some object. in this way, he got a gut feel for the physical properties of collisions and succeeded in combining his two passions\.\* on one occasion, the skate, with a mass of 129 kg, including his armor, hurled himself against a 805 kg stationary statue of isaac newton in a perfectly elastic linear collision. as a result, isaac started moving at 1.97 m/s and nate bounced backward. what were nate\'s speeds immediately before and after the collision? (enter positive numbers.) ignore friction with the ground.

    m₁v₁ + m₂v₂ = (m₁ + m₂)vmomentum is conserved.the left-hand side of the equation represents the momentum in the system before the collision.the right-hand side represents the momentum in the system after the collisionm₁ and v₁ represents the mass and the velocity of the physics blockm₂ and v₂ represents the mass and velocity of the ball of puttyv represents the final velocity of the combined mass.the question states the two masses stick together. they combined mass has its own velocity with the body mass the sum of the two objects' massestheir combined momentum is (m₁ + m₂)vto find the magitude of (m₁ + m₂)v, we need to add the vectors on the left-hand side of the equation: m₁v₁ + m₂v₂.note the diagram. i have positioned the vectors in accordance with their directions.the magnitude of the resultant can be calculated using the pythagorean theorem since this is a right triangle situation (north and west are perpendicular)|(m₁ + m₂)v| =  √[ (m₁v₁)² + (m₂v₂)² ]|(m₁ + m₂)v| =  √[ (1.5kg·8.0m/s)² + (0.40kg·20m/s)² ]|(m₁ + m₂)v| =  14.4 kg m/sfor two significant figures (assuming that 20m/s is two), this rounds to 14 kg m/s

'b ' is the correct conclusion.