Adding and Subtracting vectors; Finding change in velocity

Click For Summary
SUMMARY

The discussion centers on calculating the change in velocity of a cricket ball hit by a batsman. The initial velocity of the ball is 30 m/s towards the batsman, and the final velocity is 50 m/s towards square leg. The correct calculation of the change in velocity (Δv) is determined to be W31°N, contrasting with the incorrect answer of N59°W provided by a participant. The confusion arises from the use of trigonometric functions to determine the angle, highlighting the importance of understanding vector direction in physics.

PREREQUISITES
  • Understanding of vector addition and subtraction
  • Familiarity with trigonometric functions, specifically tangent
  • Knowledge of basic physics concepts related to velocity
  • Ability to interpret directional angles in a Cartesian coordinate system
NEXT STEPS
  • Study vector addition and subtraction in physics
  • Learn about trigonometric functions and their applications in physics
  • Explore the concept of relative velocity in different frames of reference
  • Practice problems involving angular direction and velocity calculations
USEFUL FOR

Students studying physics, particularly those focusing on mechanics and vector analysis, as well as educators looking for examples of vector calculations in real-world scenarios.

ShannonBanana
Messages
2
Reaction score
0

Homework Statement



A batsman hits a cricket ball traveling towards him at 30m/s over square leg at 50m/s. If the cricketer is facing north and square leg is west of him, what is the change in velocity of the ball?

Homework Equations



Δv= Final velocity subtract initial velocity.

The Attempt at a Solution



I've attached a picture of my working, so you might be able to see where I've gone wrong. From this diagram, I got correct the final "speed" but not the direction. My answer was Δv=58m/s N59°W, but the answer given says the direction should be W31°N.
I got my answer through tan-1(50/30) or tan-1(opposite over adjacent). To get the answer given, you would have to (by my reckoning) use adjacent over opposite, which doesn't seem to be right. Do I have θ in the right place? And, if so, why?

Thanks for the help :)
 
Physics news on Phys.org
ShannonBanana said:
N59°W, but the answer given says the direction should be W31°N.
Aren't they the same?
 
... Are you serious?? Wow, I'm feeling kind of dumb now... Thank you though! :D
 

Similar threads

Trying to understand the logic behind adding vectors with an angle between them
  • · Replies 14 ·
Replies
14
Views
2K
Adding and Subtracting Vectors of Different Directions
  • · Replies 1 ·
Replies
1
Views
2K
Motion vector subtraction, my attempts and where i'm stuck
  • · Replies 7 ·
Replies
7
Views
2K
Change in momentum when given the speed (not the velocity).
  • · Replies 2 ·
Replies
2
Views
3K
Ambiguous question on momentum and how it works...
  • · Replies 13 ·
Replies
13
Views
1K
Solving for Time to Reach Ground: Calculating Velocity of Sound over 50m
  • · Replies 2 ·
Replies
2
Views
2K
Finding the change in velocity from an acceleration vs time graph
  • · Replies 1 ·
Replies
1
Views
3K
Solving Vector Diagrams: Finding Displacements & Velocities
  • · Replies 5 ·
Replies
5
Views
2K
To find the relative velocity of the wind as seen from a car
  • · Replies 1 ·
Replies
1
Views
1K
Projectile Motion Using Vectors
  • · Replies 39 ·
2
Replies
39
Views
5K