physics help urgent please (1 Viewer)

[BFF]

I have prelim exams in a couple of days and I came across this net force/vectors question, i know this is going to be in my exam. I need to know how to do this. Any help would be appreciated.

A 50kg person flying upwards.

Person is accelarating upwards at 2 ms ^-2 and at same time accelarating horizontally at 1 ms ^-2.

a) draw vectors showing forces at the time

b) calculate the net force acting on the person flying.

 

[the-1-n-only-me]

I have prelim exams in a couple of days and I came across this net force/vectors question, i know this is going to be in my exam. I need to know how to do this. Any help would be appreciated.

A 50kg person flying upwards.

Person is accelarating upwards at 2 ms ^-2 and at same time accelarating horizontally at 1 ms ^-2.

a) draw vectors showing forces at the time

b) calculate the net force acting on the person flying.

i dunno.. im taking a guess at this.. but im assuming your upwards vector would be 7.8 (9.8-2) and you'd get a sideways vector (the question doesnt specify from which direction) and then you use pythagoras and get the hypotenuse vector.

i dunno if im right.. and i take no resposibility if im wrong

 

[chrissy697]

i had the exact same question in my yearlys (except my mass was 90kg). i cant remember exactly what i done coz i was having a major stress attack at that time but it was somehting like this: fist you have to add all the forces together to get the net force (2m/s up, 1m/s across, 9.8m/s down(gravity)) then use the total from that and the equation f=ma to find the net force acting on the guy. like i said im not quite sure exactly what i done but it was something along that process.

good luck!! and dont completely follow mine, ask ur techer n other people in ur class as well (just incase im wrong lol)

 

[BFF]

i had the exact same question in my yearlys (except my mass was 90kg). i cant remember exactly what i done coz i was having a major stress attack at that time but it was somehting like this: fist you have to add all the forces together to get the net force (2m/s up, 1m/s across, 9.8m/s down(gravity)) then use the total from that and the equation f=ma to find the net force acting on the guy. like i said im not quite sure exactly what i done but it was something along that process.

Sorry but how do you get the net force. Like I could do it if the forces were only up and down but how do you factor in the horizontal accelaration. What I thought I could of done was use the down vector of 50kg because that has gravity acting on him.and when you are putting into f=ma dont you use the mass (50) and times it by the accelaration that is the diagonal vector I assume. So would the net force would be up at an angle. But how would you find that net force.

 

[airie]

Did a diagram in Paint, the vectors are not to scale (but you probably should make them) and do not laugh at my ellipse "person"

 

[BFF]

you are the best thank you

 

[SoulSearcher]

Did a diagram in Paint, the vectors are not to scale (but you probably should make them) and do not laugh at my ellipse "person"

:rofl:

Jokes That's actually quite good. I can't do those sorts of questions

 

[airie]

You're welcome BFF

Yes, you just have to laugh at my diagram don't you, SoulSearcher?

 

[SoulSearcher]

You invited people to laugh when you told people not to laugh

 

[Forbidden.]

Not only do I not understand the diagram myself, but I see nothing funny.

EDIT: Oh it must be F_net²=590²+50², and at first I didn't fully take gravity into account

 

[airie]

Oh yes, I was kinda...short on explanation there

See SS, there's nothing funny about my diagram

 

[SoulSearcher]