Правка разделов «Statement», «Answer»
en/2.6.34.md
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| @@ -1,6 +1,6 @@ | |||
| ### Statement | |||
| − | $2.6.34.$ | ||
| + | $2.6.34.$ The kinetic energy of a satellite in a circular orbit is equal to K. What is its potential energy? | ||
| ### Solution | |||
| For a circular orbit, the gravitational force provides the centripetal force\ | |||
| $\frac{GmM}{r^2}=\frac{mv^2}{r}$\ | |||
| Cancel m and multiply by r\ | |||
| $\frac{GM}{r}=v^2$ (1)\ | |||
| The kinetic energy is\ | |||
| $K=\frac{mv^2}{2}$\ | |||
| $v^2=\frac{2K}{m}$\ | |||
| And subsituting into equation (1)\ | |||
| $\frac{GM}{r}=\frac{2K}{m}$\ | |||
| we get\ | |||
| $2K=\frac{GmM}{r}$\ | |||
| The potential energy is\ | |||
| $U=-\frac{GmM}{r}$ , so\ | |||
| $U=-2K$ | |||
| @@ -21,4 +21,4 @@Solution | |||
| #### Answer | |||
| − | [Insert a concise answer or boxed result] | ||
| + | $U=-2K$ | ||
| @@ -1,6 +1,6 @@ | |||
| ### Statement | ### Statement | ||
| $2.6.34.$ |
$2.6.34.$ The kinetic energy of a satellite in a circular orbit is equal to K. What is its potential energy? | ||
| ### Solution | ### Solution | ||
| For a circular orbit, the gravitational force provides the centripetal force\ | For a circular orbit, the gravitational force provides the centripetal force\ | ||
| $\frac{GmM}{r^2}=\frac{mv^2}{r}$\ | $\frac{GmM}{r^2}=\frac{mv^2}{r}$\ | ||
| Cancel m and multiply by r\ | Cancel m and multiply by r\ | ||
| $\frac{GM}{r}=v^2$ (1)\ | $\frac{GM}{r}=v^2$ (1)\ | ||
| The kinetic energy is\ | The kinetic energy is\ | ||
| $K=\frac{mv^2}{2}$\ | $K=\frac{mv^2}{2}$\ | ||
| $v^2=\frac{2K}{m}$\ | $v^2=\frac{2K}{m}$\ | ||
| And subsituting into equation (1)\ | And subsituting into equation (1)\ | ||
| $\frac{GM}{r}=\frac{2K}{m}$\ | $\frac{GM}{r}=\frac{2K}{m}$\ | ||
| we get\ | we get\ | ||
| $2K=\frac{GmM}{r}$\ | $2K=\frac{GmM}{r}$\ | ||
| The potential energy is\ | The potential energy is\ | ||
| $U=-\frac{GmM}{r}$ , so\ | $U=-\frac{GmM}{r}$ , so\ | ||
| $U=-2K$ | $U=-2K$ | ||
| @@ -21,4 +21,4 @@Solution | |||
| #### Answer | #### Answer | ||
| [Insert a concise answer or boxed result] | $U=-2K$ | ||