Orbital Velocity — Practice Quiz

Question 1

Orbital velocity of a satellite at r = 2R from Earth's center:

Accepted Answer

√(gR)/√2

Answer

√(gR)

Answer

√(gR/2)

Answer

√(2gR)

Question 2

If orbital radius doubles, orbital velocity:

Accepted Answer

Becomes 1/√2 times

Answer

Doubles

Answer

Halves

Answer

Stays the same

Question 3

Time period of a satellite at r = 4R (Earth) is:

Accepted Answer

T = 8 T₀ where T₀ is period at R

Answer

T = T₀

Answer

T = 2 T₀

Answer

T = 16 T₀

Question 4

Orbital velocity of a body just above Earth's surface (g = 9.8, R = 6.4×10⁶ m):

Accepted Answer

≈ 8 km/s

Answer

≈ 11 km/s

Answer

≈ 4 km/s

Answer

≈ 30 km/s

Question 5

Energy required to lift a satellite from low Earth orbit to a higher orbit at 2R is:

Accepted Answer

GMm/(4R)

Answer

GMm/(2R)

Answer

Negative (releases energy)

Answer

Zero