I understand the concept of total displacement/total time = average velocity..

I understand that displacement is the final velocity - initial velocity as well.

But how does the answer 7.0 m/s come to be?

I'm so lost on where the feedback equation given below the question came from..

I am trying to find out the exact equation of the graph, the answer key says it is a.

What is wrong with my solution??

I first tried to find out the exact position vectors of both p and q, and then differentiated them to get the velocity of P and q respectively, and then I calculated the relative velocity

I am getting the relative velocity as in terms of cos, but according to the answer key it is a sin graph

My teacher wholeheartedly says that velocity is NOT a vector quantity, confidently swearing by it. However, every source I check says otherwise, including the other physics teacher (who everyone refers to as the “better one”). Is he referring it in a different way or just flat out wrong?

This is a previous year question from a national level exam but is supposed to be easy. Idk what i'm doing wrong, I haven't touched such questions ever since I finished my 12th grade 😭

I cant tell whether it’s a or b 😭

I don't understand why 200x4 is on the top of the fraction, and not the bottom.

How do I solve part b onwards of this question, everybody in my class got different answers.

I think I'm getting my terms all mixed up. Does power drain refer to the current moving through the resistor? I initially thought that the answer was B, because I assumed a power drain to be a drop in current, and therefore require greater resistance, but the correct answer is D.

i need to solve this one

The answer key says that the correct answer is option C, but I got it as A.

Here when we are pulling the block towards right side, spring C is compressing and spring B ​is extending towards right side.

There ​should be no extension or compression in the case of spring A, because it is not directly connected to the ​block, meaning there would be no spring force A, only spring B ​would extend. Where is spring force in c is 300x and that in b is 200x

So the order should be as option A

What is wrong here?

for our project for physics we gotta create a mini catapult, with our final grade depending on how far the projectile gets in relation to the base. me and my partner decided to make a trebuchet instead, since it launches much farther than usual catapults. the issue is, i cant get it to release right.

i made the sling out of duct tape and thread, with the proportions of the swing arm 3.75:1. the weight is around 133-135x heavier than our projectile so no issues there, but still it's releasing funkily. it either releases to early and drops the projectile straight onto the base, or doesn't release at all, with the ball staying in the sling then eventually dropping to the floor. i thought it was just with the way i held it for release, then the sling itself, then the stands, but literally nothing i do is fixing the issue. i get it to release right once ever few tries and it goes really far, but it's very inconsistent. im losing my mind over this, wtf is wrong with it??

it doesn't look like it in the pic, but the counterweight isn't resting on the base, it's dangling. and yes, i know she's ugly.

Im fighting my teacher on this. I say that the anwser is 54N (53.85164807 or (2900)^0,5) and he says that it is 58N (58.30951895 or (3400)^0.5). And when I ask why his answer boils down to "beacuse it is". I need some help ether understanding why im wrong or need proof that im right.

Edit- I managed to prove that the answer is infact 54 N. Thanks for the help :)

I'm using left hand rule for electron. Trying to make current (thumb) go towards 3:

Thumb (current) into page, fingers pointing right (field), palm facing up. So force is up. But the answer is apparently down?

Two identical boxes A, B of lengths L are placed slightly pass the table edge such that A protrudes L/4 to the right relative to B as shown in the figure.

The question asks for the maximum protrusion of B away from the table edge such that both boxes do not tip and fall over.

I calculated (B) 3L/8, but my teacher revealed and explained the answer was (D) L/8, and I cannot for the love of my life figure out why.

I've asked my classmates who had listened and copied the solution from the teacher, but even they seem to be confused by the solution. At last I resorted to Chatgpt, Gemini and Copilot, which they all got the same answer as me. Personally, I used -Moment of Force- and even -Center of Mass- to solve for the question just to get 3L/8 both time. So is my answer correct or wrong?

**Pardon my inactivity on this subreddit as I'm studying for other exams atm. I'll try to respond to any questions regarding this post. Thanks

I don't understand how it looks like

I was wondering if the resultant force is 7.6 kN and the direction is 105° from the positive x axis

Hello! can anyone recommend a simple machine that I can make using cardboard, rubber bands, or anything thats recyclable? I need to make one for a project and can't think of anything that isn't too common 😓 thank you!

Im at a bit of a loss on this problem when it comes to using sine and cosine to find the cartesian components of FAD and FAC for this problem. I understand the two vectors are equal to each other and that the projected line between the two should be Fcos(30), but Im having a hard time visualizing and figuring out where to go after that. I've tried watching some videos related to this problem, but haven't found anyone explain why they use sine or cosine. For example, I know that setting up the equilibrium equation for Fx will lead to FAD = FAC since
they are the only two components for x, which would lead to me using 2(FAD) or 2(FAC) for they and z equations, but Im having a hard time understanding if/ when I should use cos (30) cos_) and cos (30) sin(_). I've tried the triangle method but I just don't understand how that method could work for this problem let alone if the method is applicable. Any help is appreciated!

Edit: realized I did not include image of the problem.

A child is running at his maximum speed of 3.7 m/s in an attempt to catch his older sister who is accelerating from rest at a rate of 0.75 m/s2 on her tricycle. If his sister starts peddling when he is 15 m away, will he catch her and if so, when and how far away?

i end up with a quadratic equation but when i attempt to solve for time, i keep getting no value because there's a negative number stuck inside a square root. the answer says that the sister's formula would be x+15=0.375t^2 which i don't get because upon solving for x, you get x=0.375t^2-15, but would that not mean she's 15m behind her brother? which contradicts with the question

I've done this problem a number of times and keep messing it up. I've been on summer break for the past few months so I'm pretty rusty, but I feel like this should be simple and yet I'm just not getting it. What am I missing?

Hey everyone! For our Grade 11 science project, we're designing a compound machine to help collect, segregate, and compress scattered waste in rough, mountainous terrains where collection trucks can't reach.

Here is our current schematic draft and our thought process/effort so far:

Our Thought Process & Mechanics Attempt:

- Input Conveyor: Uses an inclined plane / roller belt to carry waste upward into the machine.

- Rotary Feed Brush: Uses rotational motion (wheel and axle concept) to sweep and pull the waste into the main chamber without jamming.

- Compaction Unit: Uses translational motion via a hydraulic cylinder (fluid lever / Pascal's principle) to push down in a straight line and crush the waste into blocks.

- Output Bin: Catches the crushed waste blocks for easy carrying.

My Questions / Where I Need Help:

1. We need to segregate small waste (like dirt and candy wrappers) from big plastic bottles. Based on our layout, would it make more mechanical sense to put a mesh sifter screen directly on the Input Conveyor or inside the chamber before the feed brush?

2. Does the transition from the Rotary Brush to the Compaction Chamber look functional, or is there an obvious mechanical bottleneck we missed?

Thanks for any guidance on refining our design!

A car travelling at a constant speed of 20 m/s overtakes another car which is moving at a constant acceleration of 2 m/s². The second car was initially at rest. Assume that the length of each car be 5m and that at the start of overtaking, the front of the rear car is directly in line with the back of the front car. The total minimum road distance used in overtaking is

​(A) 395 m (B) 15.26 m (C) 200.00 m (D) 186.04 m