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# physics question Watch

1. Is acceleration independent of mass?
2. (Original post by Acrux)
Is acceleration independent of mass?
Yes, I'm pretty sure it is

By standard definitions, a = v-u/t, which is independent of mass
3. (Original post by kingaaran)
Yes, I'm pretty sure it is

By standard definitions, a = v-u/t, which is independent of mass
(Original post by Helpmeoutplease)
F=ma
a=F/m and so a larger mass will result in a lower acceleration provided the force is constant
https://e3ab10733179873e9fd16d54c56b...%20A-level.pdf

Question 1cii
Mark scheme says Acceleration is independent of mass, acceleration stays the same?
This doesn't accept F=ma
4. (Original post by Acrux)
https://e3ab10733179873e9fd16d54c56b...%20A-level.pdf

Question 1cii
Mark scheme says Acceleration is independent of mass, acceleration stays the same?
This doesn't accept F=ma
force of gravity is also proportional to m. so f=mgsintheta, ma=mgsintheta a=gsintheta hence is independent of mass
5. (Original post by Acrux)
https://e3ab10733179873e9fd16d54c56b...%20A-level.pdf

Question 1cii
Mark scheme says Acceleration is independent of mass, acceleration stays the same?
This doesn't accept F=ma
F is mgsinx so m cancels out in this case
6. (Original post by samb1234)
force of gravity is also proportional to m. so f=mgsintheta, ma=mgsintheta a=gsintheta hence is independent of mass
So is this the reason why Acceleration is the same even when the mass is increased?
And this is why time taken to travel distance is the same
7. (Original post by Acrux)
So is this the reason why Acceleration is the same even when the mass is increased?
And this is why time taken to travel distance is the same
yes
8. (Original post by samb1234)
yes
hey do you do chemistry
9. (Original post by Lola1244)
hey do you do chemistry
Yes why
10. (Original post by samb1234)
Yes why

One method used to inflate air bags in cars is to use nitrogen produced chemically from the decomposition ofsodium azide. The sodium formed reacts with potassium nitrate to give more nitrogen.2 NaN3(s)  2 Na(s) + 3 N2(g)10 Na(s) + 2 KNO3(s)  K2O(s) + 5 Na2O(s) + N2(g)a) In what ratio (by mass) must the sodium azide and potassium nitrate be mixed in order that no metallic sodiumremains after the reaction?b) Calculate the total mass of the solid mixture needed to inflate a 60.0 dm3air bag at room temperature andatmospheric pressure.

(the squares are arrows)

for a the answer is 1:3.11
confused a to how, if you get a chance could you look over??
11. i got 3.21:1
12. (Original post by Lola1244)
One method used to inflate air bags in cars is to use nitrogen produced chemically from the decomposition ofsodium azide. The sodium formed reacts with potassium nitrate to give more nitrogen.2 NaN3(s)  2 Na(s) + 3 N2(g)10 Na(s) + 2 KNO3(s)  K2O(s) + 5 Na2O(s) + N2(g)a) In what ratio (by mass) must the sodium azide and potassium nitrate be mixed in order that no metallic sodiumremains after the reaction?b) Calculate the total mass of the solid mixture needed to inflate a 60.0 dm3air bag at room temperature andatmospheric pressure.

(the squares are arrows)

for a the answer is 1:3.11
confused a to how, if you get a chance could you look over??
Well if for every 2 moles of nan3 we make 2 moles of Na, and 10 moles of Na will react with 2 moles of KNO3 the ratio of moles will be 10:2 =5:1 (since 10 moles of nan3 will make 10 moles of na which will be converted by 2 moles of kno3). Then you just need to convert it to a mass ratio using the molar masses
13. (Original post by samb1234)
Well if for every 2 moles of nan3 we make 2 moles of Na, and 10 moles of Na will react with 2 moles of KNO3 the ratio of moles will be 10:2 =5:1 (since 10 moles of nan3 will make 10 moles of na which will be converted by 2 moles of kno3). Then you just need to convert it to a mass ratio using the molar masses
i did that and got what i said above? think they forgot to times something by 10
14. (Original post by Lola1244)
i did that and got what i said above? think they forgot to times something by 10
Im not sure, im on my phone so i havent actually done the calculation to get to the ratio. Its probably a typo in the mark scheme

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