Recent content by sofiasherwood

This is the question given in the test word for word. The question confused me for ages, in the end I just assumed acceleration was constant. I don't know how you could work it out any other way.

Have I gone wrong somewhere?

I am assuming the acceleration is constant. Is that right?

P*t=W 12*9=108 therefore W=108joules W=F*displacement F=108/56 F=1.93N F=ma a=1.93/20 a=0.1 so at t=6 Pt=W 12*6=72joules W=72joules W=F*displacement displacement=72/(20*0.1) displacement=36m P=Fv v=12/(20*0.1) v=6

I had a test earlier today and one question was, A 20kg object initially at rest is accelerated at constant power of 12.0w. After 9.0s it has moved 56.0m. Find its speed at t=6.0s and its position at that instant. I got v=6 and distance=36m are these values correct?

Thanks for your response. I think I'm getting my head around circular motion. Yay!

Lets say we have a ball on a string and we spin it around. The ball will undergo circular motion. The tension in the string is what provides the centripetal force, directed inwards. Then what would be the force directed outwards? (According to Newton's third law of motion). It can't be...

Thanks, I mostly understand it now. Its the first time I have ever really thought about elliptical orbits, so its all new for me and a bit to get my head around.

"It is, however, to have a strictly circular orbit with tangential accelerations as well, but such orbits are NOT possible only under the influence of gravity (other forces would have to be present as well)." Would I be right in saying because the Moon is in space (a vacuum) only gravity is...

I really apologise, that last statement doesn't make sense. I am struggling to explain it. What I am basically asking is, does the tangential acceleration cause the orbit to become elliptical and not follow a circular orbit?

so basically in a circular orbit the acceleration is only directed inwards. But in a elliptical orbit, the acceleration is directed inwards and in the direction of its velocity. So is this what gives rise to a elliptical orbit and not circular orbit, because the acceleration is unbalanced or...

Cheers :-)

I understand it now. Thanks for all your help.

Thank you very much for explaining this to me. Can I also ask, centrifugal force is not a real force then why do we even use this term? Is there a reason why we have given a name to something that doesn't even exist?