At what height above Earth’s surface are gravitational potential and gravitational acceleration -5.4×10⁷ J kg⁻¹ and 6.0 m s⁻² respectively? Take Earth radius 6400 km.
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At what height above Earth’s surface are gravitational potential and gravitational acceleration −5.4×10⁷ J kg⁻¹ and 6.0 m s⁻² respectively? Take Earth radius 6400 km.

G1 Physics · Accepted Answer

Step 1: |V|=GM/r and g=GM/r², therefore r=|V|/g. Step 2: r=(5.4×10⁷)/6=9×10⁶ m=9000 km. Subtract Earth radius 6400 km to obtain h=2600 km. Final answer: D — 2600 km. The scanned PDF marks Q37 as B in its solution heading, but its numerical derivation gives 2600 km.