For this problem, we use the conservation of momentum as a solution. Since momentum is mass times velocity, then,
m₁v₁ + m₂v₂ = m₁v₁' + m₂v₂'
where
v₁ and v₂ are initial velocities of cart A and B, respectively
v₁' and v₂' are final velocities of cart A and B, respectively
m₁ and m₂ are masses of cart A and B, respectively
(7 kg)(0 m/s) + (3 kg)(0 m/s) = (7 kg)(v₁') + (3 kg)(6 m/s)
Solving for v₁',
v₁' = -2.57 m/s
<em>Therefore, the speed of cart A is at 2.57 m/s at the direction opposite of cart B.</em>
<span>The density of the energy that is transported under the waves under the ocean surface is about five times higher compared to the wind energy 20 meter (about 65 feet) above. In other words, the amount of energy in a single wave is very high. However it turns out that when they tried to make the high power of the waves to power things in a house it only made it past the first few stages there were very few that made it to some stages. This started taking place in around 2001. hope this helped if not let me know and i could explain more:)
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Momentum = (mass) x (speed)
Change in momentum = (force) x (time)
The initial momentum is (mass) x (speed) = 2500x 25 = 62,500 kg-m/s.
Since you want to <u>stop</u> the vehicle, that number is also the required <em>change</em>
in momentum ... you want the vehicle to wind up with zero momentum.
62,500 = (force) x (time) = 20 x force
Divide each side by 20 :
force = 62,500 / 20 = <em>3,125 newtons </em>
