Let the mass of 2500 kg car be
and it's velocity be
and the mass of 1500 kg car be
and it's velocity be
.
After the bumping the mass be M and it's velocity be V.
By law of conservation of momentum we have
![m_1v_1+m_2v_2 = MV](https://tex.z-dn.net/?f=m_1v_1%2Bm_2v_2%20%3D%20MV)
2500 * 5 + 1500 * 1=4000 * V
V = 14000/4000 = 7/2 = 3.5 m/s
So the velocity of the two-car train = 3.5 m/s
Answer:
7.55 km/s
Explanation:
The force of gravity between the Earth and the Hubble Telescope corresponds to the centripetal force that keeps the telescope in uniform circular motion around the Earth:
![G\frac{mM}{R^2}=m\frac{v^2}{R}](https://tex.z-dn.net/?f=G%5Cfrac%7BmM%7D%7BR%5E2%7D%3Dm%5Cfrac%7Bv%5E2%7D%7BR%7D)
where
is the gravitational constant
is the mass of the telescope
is the mass of the Earth
is the distance between the telescope and the Earth's centre (given by the sum of the Earth's radius, r, and the telescope altitude, h)
v = ? is the orbital velocity of the Hubble telescope
Re-arranging the equation and substituting numbers, we find the orbital velocity:
![v=\sqrt{\frac{GM}{R}}=\sqrt{\frac{(6.67\cdot 10^{-11})(5.97\cdot 10^{24} kg)}{6.99\cdot 10^6 m}}=7548 m/s=7.55 km/s](https://tex.z-dn.net/?f=v%3D%5Csqrt%7B%5Cfrac%7BGM%7D%7BR%7D%7D%3D%5Csqrt%7B%5Cfrac%7B%286.67%5Ccdot%2010%5E%7B-11%7D%29%285.97%5Ccdot%2010%5E%7B24%7D%20kg%29%7D%7B6.99%5Ccdot%2010%5E6%20m%7D%7D%3D7548%20m%2Fs%3D7.55%20km%2Fs)
Throw it sideways and try to make it spin around but it needs to be thrown high up then it should kinda glide down
Answer:
B. 17.15 watts
Explanation:
Given that
Time = 10 seconds
height = distance = 0.7 meters
weight of sack = mg = F = 245 newtons
Power = work done/ time taken
Where work done = force × distance
Substituting the given parameters into the formula
Work done = 245 newton × 0.7 meters
Work done = 171.5 J
Recall,
Power = work done/time
Power = 171.5 J ÷ 10
Power = 17.15 watts
Hence the power expended is B. 17.15 watts
As we know that acceleration is directly proportional to force, therefore as the force is doubled, acceleration gets doubled too.