How Do You Calculate Displacement in Physics Problems?

  • Thread starter Thread starter CanadianChick
  • Start date Start date
  • Tags Tags
    Displacement
Click For Summary
SUMMARY

The discussion focuses on calculating displacement in physics, specifically through a problem involving a series of movements in different directions. Jessie drove north, west, and south at varying speeds, and the final displacement was determined to be 28 km at an angle of 28 degrees north of west. Key methods to solve the problem include calculating individual displacements using the formula displacement = speed × time, drawing vector diagrams, and applying trigonometry to find the resultant angle using arctangent. The final answer aligns with the textbook solution, confirming the accuracy of the calculations.

PREREQUISITES
  • Understanding of basic kinematics, including speed and time relationships.
  • Familiarity with vector addition and representation.
  • Knowledge of trigonometric functions, particularly arctangent.
  • Ability to interpret and draw vector diagrams.
NEXT STEPS
  • Study the concept of vector addition in physics.
  • Learn how to apply trigonometry in solving physics problems, focusing on arctangent calculations.
  • Practice drawing and interpreting vector diagrams for displacement problems.
  • Explore kinematic equations and their applications in real-world scenarios.
USEFUL FOR

Students studying physics, particularly those in high school, as well as educators looking for effective methods to teach displacement and vector analysis.

CanadianChick
Messages
3
Reaction score
0
Need Some Help With Displacement...please =)

I'm working independently on Grade 11 Physics, and ran across a displacement question I need some help with. So here goes:

1. Jessie drove north at 45km/h for 20 min, then turned West and drove at 54km/h for 27min. Finally she drove South at 18km/h for 6.4 min. Find her displacement



2. According to my notes Displacement= the difference from final position to initial position



The final answer according to the book is 28km[W 28degrees N] but I have no idea how to get this answer. Any help would be GREATLY appreciated. Thanks!
 
Physics news on Phys.org


Draw out the displacements (displacement=speed*time) and then find the distance between the final position and the initial position. Then use trigonometry to find the angle.

So, draw a line from the origin north for the distance specified, then from there the distance west and then from the end of that distance draw the distance south. Then find the distance between where the path ended and started.

You could also write the displacements as vectors and add them together.
 


Great =) Very helpful, thanks for the quick reply.

So there's no way to calculate it without drawing the vectors, or using Trig?
 


The trig is just to find the angle, and all you really need is the arctangent.

With vectors, take the arctangent of the vertical component divided by the horizontal component.
 


Great =) thank for the help!
 

Similar threads

How Do You Calculate Total Displacement in Multi-Stage Motion Problems?
  • · Replies 3 ·
Replies
3
Views
1K
Need help with physics magnitude and displacement
  • · Replies 5 ·
Replies
5
Views
4K
Vectors: Displacement, average velocity & speed
  • · Replies 7 ·
Replies
7
Views
2K
Hints on how to approach this vector displacement problem?
  • · Replies 3 ·
Replies
3
Views
16K
Velocity vector displacement problem
  • · Replies 9 ·
Replies
9
Views
2K
How Is Average Velocity Calculated in Multi-Stage Vector Displacements?
  • · Replies 3 ·
Replies
3
Views
2K
Vector Displacement calculation
  • · Replies 3 ·
Replies
3
Views
1K
How Can We Calculate Displacement and Average Velocity for a Complex Trip?
  • · Replies 4 ·
Replies
4
Views
2K
How Do You Calculate Displacement Using Vector Components?
  • · Replies 3 ·
Replies
3
Views
2K
How Do You Calculate Displacement, Average Speed, and Velocity in 2D Kinematics?
  • · Replies 1 ·
Replies
1
Views
2K