Mechanics 1 P42 2014; Discussion!

[Oishee Asif]

What'd you have to find in part 1?

 

[Oishee Asif]

Yupp.
See the mass of the car was 600kg and the acceleration was 1.4 and the Power given to you was 22.5 kW. and v=18

D - R = ma
=> D = R + ma
=> R = D - ma
=> R = P/v - ma
Blah blah... right?

And then you substitute that into something else and wala! You get the answer.
I guess I typed something wrong in the calculator then. -___-

 

[thementor]

What'd you have to find in part 1?

A car of mass 600 kg is travelling along a horizontal road where the resistance to motion is constant and equal to R. The acceleration is 1.4 at a point when the power of the engine is 22.5kW and the speed of the car is 18/ Find R

 

[thementor]

D - R = ma
=> D = R + ma
=> R = D - ma
=> R = P/v - ma
Blah blah... right?

And then you substitute that into something else and wala! You get the answer.
I guess I typed something wrong in the calculator then. -___-

no worries. Still you get marks for the correct method,.

 

[Oishee Asif]

Sigh. :\

 

[thementor]

Sigh. :\

cheer up

 

[Oishee Asif]

cheer up

Hell naw.
There goes my chances of getting an A*.

 

[thementor]

Hell naw.
There goes my chances of getting an A*.

you still have a chance at an A*. If you're chances go, then what about me? I made a lot of mistakes in Q5?

 

[Oishee Asif]

you still have a chance at an A*. If you're chances go, then what about me? I made a lot of mistakes in Q5?

I made stupid mistakes all throughout the damn paper. :\
And d'you remember the values for the masses of the particles in #5?

 

[thementor]

I made stupid mistakes all throughout the damn paper. :\
And d'you remember the values for the masses of the particles in #5?

The 5kg one was resting on the slope. The 16 kg one was hanging from the pulley.

 

[Oishee Asif]

The 5kg one was resting on the slope. The 16 kg one was hanging from the pulley.

You, sir, have a strong memory.
Okay, well, lemme write up all the solutions, okay? And then I'll post it on here.

 

[thementor]

You, sir, have a strong memory.
Okay, well, lemme write up all the solutions, okay? And then I'll post it on here.

hahaaha. Hyper memory syndrome lol.
And yayyyyy thanks.

 

[Oishee Asif]

hahaaha. Hyper memory syndrome lol.
And yayyyyy thanks.

What was the coefficient of friction?

 

[Oishee Asif]

Never mind, got it.

 

[thementor]

What was the coefficient of friction?

1/ (sqrt(3))

 

[Oishee Asif]

SOLUTION TO NUMBER 5, M1

1/ (sqrt(3))

Ignore my poorly drawn heart.

 

[thementor]

SOLUTION TO NUMBER 5, M1


View attachment 42463

Ignore my poorly drawn heart.

awesome thankssssssssss

 

[thementor]

SOLUTION TO NUMBER 5, M1


View attachment 42463

Ignore my poorly drawn heart.

Will you be posting other solutions as well?

 

[Oishee Asif]

Will you be posting other solutions as well?

InshaaAllah

 

[Snowysangel]

P was 6150W
because at constant speed the forward force will be equal to the resistive force. So using P =FV, where F=410 and v=15

Is there ECF in m1?