Answer:
I think its last one picture
Answer:
Velocity=14[m/s]
Explanation:
We can solve this problem by using the principle of energy conservation, where potential energy becomes kinetic energy.
In the attached image we can see the illustration of the ball falling from the height of 20 meters, at this time the potential energy will have the following value.
![Ep=m*g*h\\where:\\m=3[kg]\\h=20[m]\\](https://tex.z-dn.net/?f=Ep%3Dm%2Ag%2Ah%5C%5Cwhere%3A%5C%5Cm%3D3%5Bkg%5D%5C%5Ch%3D20%5Bm%5D%5C%5C)
![Ep=3*9.81*20\\Ep=588.6[J]](https://tex.z-dn.net/?f=Ep%3D3%2A9.81%2A20%5C%5CEp%3D588.6%5BJ%5D)
When the ball passes through half of the distance (10m) its potential energy will have decreased by half as shown below.
![Ep=3*9.81*10\\Ep=294.3[m]](https://tex.z-dn.net/?f=Ep%3D3%2A9.81%2A10%5C%5CEp%3D294.3%5Bm%5D)
If we know that potential energy is transformed into kinetic energy, we can find the value of speed.
![Ek=\frac{1}{2} *m*v^{2} \\therefore\\v=\sqrt{\frac{Ek*2}{m} } \\v=\sqrt{\frac{294.3*2}{3} } \\\\v=14[m/s]](https://tex.z-dn.net/?f=Ek%3D%5Cfrac%7B1%7D%7B2%7D%20%2Am%2Av%5E%7B2%7D%20%5C%5Ctherefore%5C%5Cv%3D%5Csqrt%7B%5Cfrac%7BEk%2A2%7D%7Bm%7D%20%7D%20%5C%5Cv%3D%5Csqrt%7B%5Cfrac%7B294.3%2A2%7D%7B3%7D%20%7D%20%5C%5C%5C%5Cv%3D14%5Bm%2Fs%5D)
Answer:
43.75 miles must a person walk to utilize the energy in (“burn”) a pound of fat.
Explanation:
3,500 calories are present in 1 pound of the fat.
Thus, given that:
<u>4 calories are burnt in 1 minute of walking.</u>
So,
1 calories are burnt in 1/4 minute of walking.
Or,
<u>1 calories are burnt in 0.25 minute of walking.</u>
Thus,
<u>3500 calories are burnt in 0.25*3500 minutes of walking</u>
Minutes of walking needed to burn 3500 calories = 875 minutes.
Also, given that:
<u>20 minutes of walking covers 1 mile.</u>
<u>1 minute of walking covers 1/20 mile.</u>
So,
<u>875 minutes of walking covers (1/20)*875 mile.</u>
<u>43.75 miles must a person walk to utilize the energy in (“burn”) a pound of fat.</u>
The answer is C
Hope this help
Gravitational force equals GMm/r^2, where G is constant, M and m are the masses, and r is distance.
For I, if both masses double, the formula becomes G2M2m/r^2, or 4GMm/r^2. Therefore, the gravitational force will quadruple or 4x.
For II, if the distance between the object doubles, the formula becomes GMm/(2r)^2 or GMm/4r^2. In this case, the gravitational force is 1/4x the initial force.
