- A 16.0 kg canoe moving to the left at 12.5 m/s makes an elastic head on collision with a 14.0 kg raft moving to the right at 16.0 m/s.
- After the collision the raft moves to the left at 14.4 m/s assuming water simulates a frictionless surface.
- Mass of the canoe (m1) = 16 Kg
- Mass of the raft (m2) = 14 Kg
- Initial velocity of the canoe (u1) = 12.5 m/s
- Initial velocity of the raft (u1) = - 16 m/s [Here, the raft's velocity is negative, because the objects are moving in the opposite direction]
- Total momentum of the system = m1u1 + m2u2 = [(16 × 12.5) + (14 × -16)] Kg m/s = (200 - 224) Kg m/s = -24 Kg m/s
- Final velocity of the raft (v2) = 14.4 m/s
- Let the final velocity of the canoe be v1.
- Total momentum of the system after the impact = m1v1 + m2v2 = [(16 × v1) + (14 × 14.4)] Kg m/s = 16v1 Kg + 201.6 Kg m/s
- According to the law of conservation of momentum, Total momentum of the system before the impact = Total momentum of the system after the impact
- or, -24 Kg m/s = 16v1 Kg + 201.6 Kg m/s
- or, -24 Kg m/s - 201.6 Kg m/s = 16v1 Kg
- or, -225.6 Kg m/s = 16v1 Kg
- or, v1 = -225.6 Kg m/s ÷ 16 Kg
- or, v1 = -14.1 m/s
<u>Answer:</u>
<u>T</u><u>he final velocity of the </u><u>canoe </u><u>is </u><u>-</u><u>1</u><u>4</u><u>.</u><u>1</u><u> </u><u>m/</u><u>s </u><u>or </u><u>1</u><u>4</u><u>.</u><u>1</u><u> </u><u>m/</u><u>s </u><u>to </u><u>the </u><u>right.</u>
Hope you could get an idea from here.
Doubt clarification - use comment section.
Answer:
216.31 (the work done by gravity is -216.31) positive for going up.
Explanation:
We look at this question first by getting the right equation for <em>work</em>.
Which should be... W = F x D.
From this, we can do everything, we need the Force (F) first - the question tells us that Joe is lying on his back and moves his arms upward to raise the barbell. This means that he is countering the force of graving on the object.
What is the formula for the force of gravity on an object near the earth?
Right here --- = mg
m = the mass and...
g = the acceleration due to gravity which is <em>9.81 m/s2</em>
Before we plug things in though, we need to convert everything to SI units,
the weight is in kg - so we're good to go there, but the length of Joe's arms are in "cm" we need m or meters. Converting 70 cm to m = .7 m.
Now, we just put it all together - (31.5kg)(9.81m/s2)(.7m) = 216.31 J or 216.31 N m.
The ratio of output force to the input force is generally the mechanical advantage of the machine.
It's by number of protons