# Search results

1. ### The central difference method! Help!

Hi guys. Ok I'm working on this problem, it's more theoretical than anything.:yuck: I'll try to explain as best I can. Lets say you have a runner going past the following points up till and past 30 m: Distance (x) of x1=0, x2=4, x3=9, x4=20, and x5=30m the times to these intervals are 0...
2. ### Confirm my logic on power

Ok, So, lets say I was to drag a 40kg load in a set distance of 10 meter. I record the time, it was 5 secs. Now I find power, P=work/t. We know work=force x distance. SO my question is, is force just mass of load x acceleration due to gravity? 9.81m/s^2. So P= ((40kg x 9.81) * 10...
3. ### Conceptual problem! Check my work :P

Hey:smile: , The question: The athlete on the diagram (linked) is free in the air and has a total angular momentum as indiated by the red vector. 1)Indicate with a vector the direction of his twist based on his orientation and angular momentum, show how you got this. 2)Describe 2...

Title threads.... How come I can't edit my title threads anymore. I used to be able to do it. :confused:
5. ### Finding MY center of mass!

Hi, Ok so we were told to find our center of mass using the reaction board method, but modified. We just do a pushup position with our hands on a scale, I have a electronic one and toes on the floor. My values obitained are: weight=68kg the scale reading in a pushup position=48.9kg...
6. ### Harsh Torque problem. Check for me :o)

The question is: You are wearing a special 10 kg weight boot on each of your feet and you're sitting on a table with your legs hanging over the edge at the knee joint. The knees are held at an angle of 180 degrees (straight out) and 135 degrees. In each case how much force must be produced by...
7. ### Vertical Jump Test and physics! Check My Work

Ok :rofl: , I had to test my maximum vertical jump. I did three trials and here's what I got: -Maximum standing height (ie without jumping reaching with one hand) = 221.5 cm -Maximum jumping height with one hand (best of three) = 270 cm -Net Height 270-221.5 cm = 48.5 cm, 0.485m My weight...
8. ### Ok, a little shoe experiment!

Ok, a little experiment! Ok, so I want to test the coefficient of static friction for two different kinds of shoes. I'll be using a runners and a formal dress shoe. Is this an ok procedure? :rolleyes: I'll using a wooden cherry board, and placing that against a wall. I'll slowly increase...
9. ### Quick concept question

Quick concept question!! Ok, How does the current relate to the speed. So lets say everything is normal and if I reduced the speed by 1/3 what would happen to my current? Thanks! :cool:
10. ### Electric Circuit help

Electric Circuit help!! Ok here's my question: For the cirucit shown in the drawing(attached), find the current (I) through the 2.00 ohm resistor and the voltage (V) of the battery to the left of this resistor. Ok, should I be using Kirchoff's drop=rise, and junction rules? It doesn't...
11. ### Looking for some help

Ok this question is kinda weird b/c I don't think there's enough info, even though there probably is: One heater uses 340W of power when connected by itself to a battery. Another heater uses 240 W of power when connected by itself to the same battery. How much total power do the heaters use...
12. ### Someone verify?

I have two charges, one is -16uC and the other +4uC. They are separated by 3.0m. I have to find the point in which the electric field is = 0 . Is my diagram here correct? (I mean are the lengths of the arrows correct with respect to magnitude of attraction between the two) -16uC...
13. ### Don't Know Where to Start

Yay, hopefully I can gather some pointers for this question. A lighter-than-air balloon and its load of passengers and ballast are floating stationary above the earth. Ballast is weight (of negligible volume) that can be dropped overboard to make the balloon rise. The radius of this balloon...
14. ### Did I do this right?

Did I do this right?? Hello, this is my work for the this question: A pendulum is constructed from a thin, rigid and uniform rod with a small sphere attached to the end opposite of the pivot. This arrangement is a good approximation to a simple pendulum (period=0.66s),m because the mass...
15. ### Quick conceptual help!

Ok, I don't understand why in a sound resonating pipe, that the in the closed end there needs to be a node and not antinode. Why?
16. ### Need someone to look at my work!

Hey to all those that enter this thread! Anyway, I have 3 questions, all of which I have done the work for, but don't know if it's correct, take a look and give some feedback. Thanks. 1)A mine car, whosse mass is 440kg, rolls at a speed of 0.50m/s on a horizontal track. A 150kg chunk of...
17. ### Fixed action patterns Qand hopefully A.

Hey people :rofl: , I have a question. Here is the Q: Question 3: (4 points) Many baby birds have specific feeding responses that are fixed action patterns elicited by a particular sign stimulus. Nestling starlings are more likely to make a fixed action pattern orienting response...
18. ### Physics Guidance

Hey Physics Experts! I got 2 questions which I did my work, but want to double check with someone, anyone! Q:A rescue helicoper lifts a 79 kg person straight up by means of a cable. The person has an upward acceleration of 0.70m/s^2 and is lifted from rest through a distance of 11m. a)what...
19. ### What force must provide the centripetal acceleration of the block?

physics help!!! Ok here's the question: A block is hung by a string from the inside roof of a van. When the van goes straight ahead at a speed of 28m/s, the block hangs verticaly down. But when the van maintains this same speed around an unbanked curve of radius 150m, the block swings toward...