Thank you for your help. I used the quoted value from the textbook but I’ve just spotted that value for copper below it is identical so it could be a mistake in the book. Thanks again
I’m fine with part a, answer 3.3 x10^6 but I’m getting 0.00045 for part b when it should be 2.8x10^-4, what am I missing?
e = (1500x18)/(1.3x10^11 x 0.000452389)
The answer is 127.04g. I’m getting close but can’t get the answer.
Using 9.81 for gravity, the force where the balance is is 2.10(58146)N
As it is balanced
2.10N x 0.29m = W x 0.50m where 0.50 is the centre of mass
That gives W = 1.22N
= 124.5g?
I've just read somewhere that acceleration is zero when an object is at terminal velocity? I think it's wrong but wanted to check if I'm right?
Yes the resultant force is zero but gravity doesn't disappear so presumably acceleration due to gravity is constant? Terminal velocity means constant...
Homework Statement
An electric circuit consists of 3 identical resistors of resistance R connected to a cell of emf E and negligible internal resistance. What is the magnitude of the current in the cell? (in the diagram two of the resistors are in parallel with each other then the other in...
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It's definitely v I need to find. According to my text book us is the moving source velocity. In the other equation it uses uo as moving observer velocity.
Homework Statement
Problem: a car is moving away from a stationary observer at 25ms^-1. It emits a frequency of 810Hz and the observer hears an apparent frequency of 762Hz. What is the speed of sound in air at that time?
Homework Equations
The equation for a source moving away is
f' =...
Homework Statement
Please could someone check if I have got this right? Many thanks
The question: An object of mass of 1000kg leaves a 64m high cliff at 100 ms-1 before descending to the ground. Ignoring air resistance, determine its speed immediately before landing.
Homework...
Trying to work out how to do this. I know the answer is B but don't know how.
Internal resistance is negligible so I assume I just use I =V/R. I've tried using sample values for R eg 5 and V =10V giving I as 1.3 but am no closer to 2/3. What am I missing?
I'm revising attenuation and power loss logarithmic equations.
The exam formula I'm given is attenuation = 10 log (I1/I2)
I'm trying to confirm what each I stands for.
Some of the examples I'm looking at seen to give input/output power, some seem to reverse it. Which is right? What do they...
Lucy stands on the edge of a vertical cliff and throws a stone vertically upwards. The stone leaves her hand with speed 15m/s at the instant her hand is 80m above the surface of the sea. Air resistance is negligible and the acceleration of free fall is 10m/s/s.
First part is to calculate the...