Oh yes! So I was in fact using the wrong equation. All I needed to do was re-arrange the work = force * distance equation to give force = work / distance. Makes sense now, thanks so much!
That equation is unfortunately not on our syllabus :( We are only allowed to use Acceleration = Change in velocity / time. How would you implement into this equation? (or f=mxa)
d) So as there is a bigger current, the filament lamp heats up. In turn, the increase in temperature results in the increase in resistance? So how does voltage come into this relation? Does the voltage increase as the current increases, or vice versa? :S
Acceleration is the rate of the change of velocity over time.
But the question doesn't state the time. Understandably because it is asking for the braking force. Aah ok. Thanks!
How do I work out the braking force given the following information:
Calculate the average braking force acting...
I used the equation Force = Mass x Acceleration. The mass of the car is 800 kg, but the units of acceleration are m/s squared? And the speed of the car is 20 m/s, the units are not m/s squared. So would I leave it at 20 m/s or convert it to suit the acceleration units?
Oh so going by that...
b) ok thanks!
c + d have been changed to links so they can be easily accessed now
e) does overheating of the wires cause an electrical fire? and the circuit breaker...uhm...it breaks the circuit?...? :S
f) ok will do thanks!
It's soft? But I thought the airbag on impact can cause injuries itself? Although it prevents the driver from coming into contact with the steering wheel? :S
Please help -- review questions
Hi there. I have an exam TOMORROW. I have prepared a lot but I just really need to understand the following in order to do the best I can:
b) Calculate the average braking force acting on a car of 800 kg to bring it to rest if it was traveling at 20 m/s – I...
Sorry for late reply. Thanks for help all. But how exactly does one understand difficult concepts? I've tried applying to reality and visualizing, looking for answers within textbooks etc. nothing helps.
Seriously confused, please help!
Hi there. These are just a few questions I just can’t get my head around. I don’t understand HOW:
a) HOW an air bag reduces injury exactly – Question says ‘Explain how an air bag reduces the risk of head injury in an accident’ – I know that the air bag inflates...
A sample of an ancient rock contains one atom of lead for every atom of uranium. the uranium in the rock has a half - life of 4500 million years. It decays to form lead which is not radioactive. Explain why the age of the rock is 4500 million years.
I assumed that 1 x 4500 million years = 0.5...
These are just a few practice questions I found difficult, I would appreciate it if you could provide step-by-step explanation on how to solve the following problems. I checked all my answers in the textbook and got the following wrong, but cannot work out how to arrive at the right answer...