Hi,my cousin just gave me this to solve as a dare,thinking I couldn't:

If a force(f) is expressed as 10i+5j such that it causes an acceleration of a =4i+j,find the mass the force will act on with such acceleration. I got an answer of 2.71kg after dividing the magnitudes of both vectors. Am I correct?

This is serious please

Omo e don tey

Oluwasaeon:
Omo e don tey

.

Like maad. Can you help?

COOL10:
.

Like maad. Can you help?

I swear no

Oluwasaeon:

I swear no

.

Aiit man no p. Thanks for dropping by. I hope others will be able to help confirm

You are correct

COOL10:
Hi,my cousin just gave me this to solve as a dare,thinking I couldn't:

If a force(f) is expressed as 10i+5j such that it causes an acceleration of a =4i+j,find the mass the force will act on with such acceleration. I got an answer of 2.71kg after dividing the magnitudes of both vectors. Am I correct?

This is serious please

m =F/a and m has only magnitude.

Hence

m = Modulus F / Modulus a

m = |√10²+5²|/ |√4²+1²|

√125/√17 = 2.71kg

Vector if I can still recall

COOL10:
Hi,my cousin just gave me this to solve as a dare,thinking I couldn't:

If a force(f) is expressed as 10i+5j such that it causes an acceleration of a =4i+j,find the mass the force will act on with such acceleration. I got an answer of 2.71kg after dividing the magnitudes of both vectors. Am I correct?

This is serious please

correct

correct

Lol. You are wrong. It's impossible for that exact force to "directly" cause such an acceleration. Remember that mass is a scalar and force(vector) is a scalar multiple of acceleration(vector) ie. F = m a . This show that the acceleration must be in the same direction as the force that's causing it.

So given that such force isn't in the same direction with the object, the question to ask is "what vector component of the force F = 10 i + 5 j is acting in the direction of the acceleration a = 4 i + j ?" that vector component is the force F' = (1/17)[180 i + 45 j ]. So you will get your mass by looking for the scalar m that satisfies F' = m a by using component equality. So

(180/17) = m(4) or (45/17) = m(1)

The mass is (45÷17)kg = 2.65kg (3 s.f)

chiefolododo:
You are correct

.

Thanks

femi4:
m =F/a and m has only magnitude.

Hence

m = Modulus F / Modulus a

m = |√10²+5²|/ |√4²+1²|

√125/√17 = 2.71kg

.

Thanks

KingErnesto:
correct

.

Thanks man

Martinez39:
Lol. You are wrong. It's impossible for that exact force to "directly" cause such an acceleration. Remember that mass is a scalar and force(vector) is a scalar multiple of acceleration(vector) ie. F = m a . This show that the acceleration must be in the same direction as the force that's causing it.

So given that such force isn't in the same direction with the object, the question to ask is "what vector component of the force F = 10 i + 5 j is acting in the direction of the acceleration a = 4 i + j ?" that vector component is the force F' = (1/17)[180 i + 45 j ]. So you will get your mass by looking for the scalar m that satisfies F' = m a by using component equality. So

(180/17) = m(4) or (45/17) = m(1)

The mass is (45÷17)kg = 2.65kg (3 s.f)

.



This is the only contrary opinion I've gotten so far(both online and offline),bro. How sure are you the force isn't in the same direction as the acceleration? I can recall that there's nothing like vector division so the only reasonable thing to do was to find their magnitudes and divide them to get the mass

COOL10:
.



This is the only contrary opinion I've gotten so far(both online and offline),bro. How sure are you the force isn't in the same direction as the acceleration? I can recall that there's nothing like vector division so the only reasonable thing to do was to find their magnitudes and divide them to get the mass

Martinez39 is right.

COOL10:
.



This is the only contrary opinion I've gotten so far(both online and offline),bro. How sure are you the force isn't in the same direction as the acceleration? I can recall that there's nothing like vector division so the only reasonable thing to do was to find their magnitudes and divide them to get the mass

The direction of a vector in the plane is given by the angle θ it makes with the positive direction of the x-axis. The direction of the vector V = X i + Y j is given by finding θ in the equation tan θ = Y ÷ X .

Try this with both vectors and you won't get the same θ . Another technique is to observe that if two vectors, say V and T , are pointing in the same direction, then there exist a positive scalar k Such that V = k T . Consequentially , T = (1/k) V .

barbiesparkz2:


Martinez39 is right.

This is the correct answer. The Op solved it direct which is wrong.


When solving questions such as this, first know the direction it's going having known the newton's second law.


Nice one.


There is no need for me to solve it as someone else's has solved it but just gonna drop this

barbiesparkz2:


Martinez39 is right.

.


I get it now after seeing the diagram. Thanks

Kylekent59:




This is the correct answer. The Op solved it direct which is wrong.


When solving questions such as this, first know the direction it's going having known the newton's second law.


Nice one.


There is no need for me to solve it as someone else's has solved it but just gonna drop this

.

femi4:
m =F/a and m has only magnitude.

Hence

m = Modulus F / Modulus a

m = |√10²+5²|/ |√4²+1²|

√125/√17 = 2.71kg

.


This was what I thought as well,but using the diagram,it's quite different.

COOL10:
.


This was what I thought as well,but using the diagram,it's quite different.

sure that's true...its been long I tackled question like this.

A lot of factors have to be put into consideration i.e acc along the direction of force.

So a will be 1/√17 (4i + j)

And F in direction of a =10i + 5j . 1/√17 (4i+j)
= 40/√17 + 5/√17 = 45/√17

So, m = 45/√17 * 1/ √17 = 45/17 = 2.65kg

the answer is 56.94 Joules. thank me later

anochuko01:
the answer is 56.94 Joules.
thank me later

bros...dem dey measure mass in joules in your village ni

femi4:
bros...dem dey measure mass in joules in your village ni

better sit and learn

femi4:
sure that's true...its been long I tackled question like this.

A lot of factors have to be put into consideration i.e acc along the direction of force.

So a will be 1/√17 (4i + j)

And F in direction of a =10i + 5j . 1/√17 (4i+j)
= 40/√17 + 5/√17 = 45/√17

So, m = 45/√17 * 1/ √17 = 45/17 = 2.65kg

.





Same here. Thanks

anochuko01:
the answer is 56.94 Joules.
thank me later

.

No,it's 14.67 watts. Nonsense

Martinez39:
Lol. You are wrong. It's impossible for that exact force to "directly" cause such an acceleration. Remember that mass is a scalar and force(vector) is a scalar multiple of acceleration(vector) ie. F = m a . This show that the acceleration must be in the same direction as the force that's causing it.

So given that such force isn't in the same direction with the object, the question to ask is "what vector component of the force F = 10 i + 5 j is acting in the direction of the acceleration a = 4 i + j ?" that vector component is the force F' = (1/17)[180 i + 45 j ]. So you will get your mass by looking for the scalar m that satisfies F' = m a by using component equality. So

(180/17) = m(4) or (45/17) = m(1)

The mass is (45÷17)kg = 2.65kg (3 s.f)

you are not wrong, but the approach for secondary school lads is the way the op solved it

quite cheap though,
I don't think you needed the assistance of gurus,because you solved it,although it was with an elementary approach,which was why your answer was slightly different.

Chidorx60:
quite cheap though,
I don't think you needed the assistance of gurus,because you solved it,although it was with an elementary approach,which was why your answer was slightly different.

E don tey jare. No mind me. Just wanted to be totally sure so I could laugh in the guy's face. Which I did today,by the way

Chidorx60:
quite cheap though,
I don't think you needed the assistance of gurus,because you solved it,although it was with an elementary approach,which was why your answer was slightly different.

He didn't solve it and his answer was plain wrong. His approach was wrong and it defied the understanding of vectors. His answer being slightly different was just a coincidence.