Liz (mL=44 kg) and James (mJ=39 kg) are floating in space at rest. Liz throws a toolbox (mt=20 kg) to James at 31 m/s to the right For which systems is the momentum in the horizontal direction the same before and just after James catches the toolbox? Only James Only the Toolbox James and Toolbox None of the above 3)What is the velocity of James just after catching the toolbox? 15.9 m/s to the left 10.5 m/s to the left 31 m/s to the left 0.525 m/s to the left 0 15.9 m/s to the right 10.5 m/s to the right 31 m/s to the right 0.525 m/s to the right 4)Rob (mC=72 kg) and Stephanie (mD=66 kg) are in a canoe (mcanoe = 30 kg) that starts at rest (Rob and Stephanie are fixed to the canoe, which pushes and pulls them along with the canoe). Stephanie throws a football (mball=1.5 kg) to Rob. Stephanie throws the ball so that it has a velocity of 27 m/s to the left. Which systems have horizontal momentum conserved from the time just before Stephanie throws the ball until just after she throws the ball? Only Rob

The correct answers to the question are

1) James and the Toolbox

3) 10.51 m/s to the right

4) Rob, Canoe, Ball and Stephanie

Explanation:

1) Since Liz and James are floating in space, the the momentum in the horizontal direction is  the same before and just after James catches the toolbox for James and the Toolbox

3) The initial momentum of the toolbox is

Momentum = mass*velocity = 20 kg*31 m/s = 620 kg·m/s

Momentum of James and the toolbox

= (Mass of James +Mass of toolbox)*Velocity

(39 + 20) * Velocity

Initial momentum = final momentum, therefore we have

59 V = 620 kg·m/s or v =620/59 =10.51 m/s to the right

4) Here, the momentum of the system includes both that of Rob, Canoe, the Ball and Stephanie because they are all stationary relative to each  other

dec 23, 2016 - a load of bricks weighing 680 n a distance of 10 m across a parking lot. if if the worker pushes the cart with a constant force of 209 n, what work= force x distance = 220 n x 10 m = 2200 n.m = 2200 j i don't know where the person got it from, but the initial part, work= force x distance me.