• Support PF! Buy your school textbooks, materials and every day products Here!

What's the Total Force Exerted on the Skater?

  • #1

Homework Statement


"Consider the 65.0-kg ice skater being pushed by two others as shown in the figure below."
Figure: https://gyazo.com/9d7525071f54b00ea7e720abdeb50594
upload_2018-10-8_18-17-2.png


Find the total force exerted on her by the others, given that F1 = 21N and F2 = 36N. Express your answer in vectorm form.


Homework Equations


I doubt "F=ma" is relevant for this question considering we're merely calculating the force directed towards the skater instead of her movement thereafter.


The Attempt at a Solution


I calculated the components of F1 and F2 with the following numbers:
I judged the angle of F1 to be (360 - 24 = 336).
F1: 21cos336 (x-component) + 21sin336 (y-component).
I judged the angle of F2 to be (90 - 24 = 66).
F2: 36cos66 (x-component) + 36sin66 (y-component).
I calculated the sum of these as 33.84i + 24.35j.
Judging by the picture, are my translations of the angles correct?
Any guidance is appreciated.

 

Attachments

Last edited by a moderator:

Answers and Replies

  • #2
RPinPA
Science Advisor
Homework Helper
565
318
Yes, your analysis of the angles is correct and thus your expressions for the components of ##F_1## and ##F_2## are correct. I haven't checked the numerical calculation but I always consider that to be a small part of the solution.
 
  • #3
CWatters
Science Advisor
Homework Helper
Gold Member
10,529
2,295
The axis appear to be labeled X , Z rather than X, Y.
 
  • #4
gneill
Mentor
20,792
2,770
The axis appear to be labeled X , Z rather than X, Y.
Well spotted. And notice the direction of +Z axis :wink:
 
  • #5
Aha! That was mildly clumsy of me. I apologize. I appreciate your keen eyes. With this new information, I will redo my calculations. Thank you for your contributions.
 

Related Threads on What's the Total Force Exerted on the Skater?

Replies
5
Views
4K
Replies
8
Views
1K
Replies
8
Views
4K
Replies
3
Views
1K
Replies
3
Views
4K
Replies
1
Views
1K
Replies
5
Views
5K
Replies
3
Views
1K
Top