Find the angle so that it seems that Mars is approaching to you

Click For Summary
SUMMARY

The discussion centers on calculating the relative velocity of Mars as it approaches an observer using the formula ##v_{M/S}=v_M - v_S##. The velocity of Mars is given as ##v_M = (-24.1;0)##, while the velocity of the observer, ##v_S##, is calculated using trigonometric functions as ##v_S=(-19.3 sin 30°;19.3 cos 30°)##. The participants confirm that with the three sides of the triangle formed by the velocities, one can determine the angle ##\beta##. The relationship between time until collision and proportional distances and velocities is also established.

PREREQUISITES
  • Understanding of vector mathematics and relative velocity
  • Knowledge of trigonometric functions and their applications
  • Familiarity with the concept of triangle properties in physics
  • Basic principles of celestial mechanics
NEXT STEPS
  • Study vector addition and subtraction in physics
  • Learn about the Law of Cosines for triangle angle calculations
  • Explore celestial mechanics and orbital dynamics
  • Investigate the effects of relative motion in astrophysics
USEFUL FOR

Astronomy enthusiasts, physics students, and anyone interested in understanding the dynamics of celestial bodies and their relative motions.

Like Tony Stark
Messages
182
Reaction score
6
Homework Statement
The spaceship S approaches Mars following the trajectory ##b−b## with velocity ##19.3 km/s## with respect to the Sun. If Mars has a velocity ##24.1 km/s## along the trajectory ##a−a## with respect to the Sun and the angle between ##b-b## and ##a-a## is ##30°## determine the angle between ##SM## and ##b−b## such that a person inside the spaceship "sees" that Mars is moving towards him
Relevant Equations
##v_{M/S}=v_M - v_S##.
I know that ##v_{M/S}=v_M - v_S##. I also know that ##v_M = (-24.1;0)##. Then, using some trigonometry, ##v_S=(-19.3 sin 30°;19.3 cos 30°)##.
So I can find ##v_{M/S}##. But that doesn't tell me anything about the angle ##\beta##.
 

Attachments

  • 20190906_202027777.jpg
    20190906_202027777.jpg
    19.8 KB · Views: 253
Physics news on Phys.org
You have all three sides of a triangle, you can find the angles.
 
mfb said:
You have all three sides of a triangle, you can find the angles.
What triangle are you talking about? The one formed by the ##v_S##, ##v_M## and ##v_{M/S}##?
 
Yes. The time until you and Mars collide is fixed, so distances and velocities are proportional to each other.
 

Similar threads

  • · Replies 1 ·
Replies
1
Views
1K
Replies
2
Views
2K
  • · Replies 20 ·
Replies
20
Views
1K
Replies
11
Views
3K
  • · Replies 9 ·
Replies
9
Views
1K
  • · Replies 15 ·
Replies
15
Views
1K
  • · Replies 6 ·
Replies
6
Views
4K
  • · Replies 36 ·
2
Replies
36
Views
4K
Replies
15
Views
2K
  • · Replies 6 ·
Replies
6
Views
3K