Question

The maximum and minimum distances of a comet from the sun are and$1.6 \times 10 ^ { 12 } \mathrm {~m}$. If its velocity when nearest to the sun is 60 m/s, what will be its velocity in m/s when it is farthest

• A. 12
• B. 60
• C. 112
• D. 6

Answer 1

Answer: (A)

12

Answer 2

By conservation of angular momentum mvr

= constant

$v _ { \min } \times r _ { \max } = v _ { \max } \times r _ { \min }$

∴$v _ { \min } = \frac { 60 \times 1.6 \times 10 ^ { 12 } } { 8 \times 10 ^ { 12 } } = \frac { 60 } { 5 } = 12 \mathrm {~m} / \mathrm { s }$