1.

The mass of the earth is `6xx10^(24)kg` and that of the moon is `7.4xx10^(22)kg`. The potential energy of the system is `-7.79xx10^(28)J`. The mean distance between the earth and moon is `(G=6.67xx10^(-11)Nm^(2)kg^(-2))`A. `3.8xx10^(8)m`B. `3.37xx10^(6)m`C. `7.6xx10^(4)m`D. `1.9xx10^(2)m`

Answer» Correct Answer - A
Here, Potential energy of system,
`U=-7.79xx10^(28)J`
Mass of the earth, `M_(E)=6xx10^(24)kg`
Mass of the moon, `M_(M)=7.4xx10^(22)kg`
The potential energy of the earth-moon system is
`U=-(GM_(E)M_(M))/r`
Where `r` is the mean distance between earth and moon.
`:. r=-(GM_(E)M_(M))/U`
`=-(6.67xx10^(-11)xx6xx10^(24)xx7.4xx10^(22))/(-7.79xx10^(28))`
`=3.8xx10^(8)m`


Discussion

No Comment Found

Related InterviewSolutions