Magnitude and direction of the resultant force

AI Thread Summary
The discussion focuses on calculating the resultant force and velocity from given forces and motion scenarios. For the forces exerted on a box, the resultant force was determined to be 142.6 N at an angle of 165.2 degrees using vector components. In the boat scenario, the resultant velocity was calculated as 8.5 m/s at 289.3 degrees, with momentum found to be 1623 kgm/s. It was noted that the direction of momentum should align with the velocity direction. The participant indicated a commitment to engaging in physics discussions on the forum.
Klutch
Messages
2
Reaction score
0
1. Three ropes are tied to a box and three boys exert the following forces:
F1=220 N @ 90 degrees
F2=185 N @ 165 degrees
F3=235 N @280 degrees

Determine the magnitude and direction of the resultant force.


For my solution I made a Vector Componant table, found the total force on the x and y axis. Transferred that to a diagram and found the resultant force to be 142.6 N in a direction of 165.2 degrees.

2. You head across the Battle River in your boat with a velocity of 8.0 m/s, south. The river is flowing at 2.8 m/s, east.

a) Determine the magnitude and the direction of the resultant velcity vector.
b)Assume that you and you boat have a total mass of 192 kg. Calculate the direction of the momentum of you and your boat as you cross the river.


This question seemed to be really simple. I got the resultant velocity to be 8.5 m/s in a direction of 289.3 degrees. For the next part I found the momentum to be 1623 kgm/s, and wouldn't the direction be the same as the velocity?
 
Physics news on Phys.org
Yeah, I didn't check it but it looks as though everything is correct. For the boat you should include the direction (i.e. 19.3 degrees east of south or whatever the angle was relative to).
 
Last edited:
Alright Thanks, and a little heads up for everyone here. I'll be one these forums alot, because I'm taking Physics by correspondance.
 
Kindly see the attached pdf. My attempt to solve it, is in it. I'm wondering if my solution is right. My idea is this: At any point of time, the ball may be assumed to be at an incline which is at an angle of θ(kindly see both the pics in the pdf file). The value of θ will continuously change and so will the value of friction. I'm not able to figure out, why my solution is wrong, if it is wrong .
Thread 'Voltmeter readings for this circuit with switches'
TL;DR Summary: I would like to know the voltmeter readings on the two resistors separately in the picture in the following cases , When one of the keys is closed When both of them are opened (Knowing that the battery has negligible internal resistance) My thoughts for the first case , one of them must be 12 volt while the other is 0 The second case we'll I think both voltmeter readings should be 12 volt since they are both parallel to the battery and they involve the key within what the...
Thread 'Trying to understand the logic behind adding vectors with an angle between them'
My initial calculation was to subtract V1 from V2 to show that from the perspective of the second aircraft the first one is -300km/h. So i checked with ChatGPT and it said I cant just subtract them because I have an angle between them. So I dont understand the reasoning of it. Like why should a velocity be dependent on an angle? I was thinking about how it would look like if the planes where parallel to each other, and then how it look like if one is turning away and I dont see it. Since...
Back
Top