# Recent content by willingtolearn

1. ### Stargazing Question on Refractor Telescope !

And one last question, why the image is inverted ? which is up side down
2. ### Stargazing Question on Refractor Telescope !

Thanks all ! Now i'm start building it
3. ### Stargazing Question on Refractor Telescope !

Thanks ! But i couldn't find the answers for my questions from that. Help please ?
4. ### Stargazing Question on Refractor Telescope !

I am plan on building a small refractor telescope about 20 cm long, i need your guys help ! 1. What len is use for Objective len and what len is use for Eyepiece len ? (how is it look like) 2. How far should i place objective len and eyepiece len apart ? 3. If i make a 20 cm long refractor...
5. ### KE and PE Work

#1 No, I haven't studied the dot product yet A) HOw much work is done by the gravitational force ? b) Ho much work is done by 100 N force ? c) What is the change in kinetic energy of the crate ? d) What is the speed of the crate after it is pulled 5 m? Sorry about that
6. ### KE and PE Work

#1 A 10kg crate is pulled up a rough incline with an initial speed of 1.5 m/s. The pulling force is 100Nparallel to the incline, which makes an angle of 20* with the horizontal. If the coefficient of kinetic friction is .40 and the crate is pulled a distance of 5 m. a)HOw much work is done by...
7. ### Acceleartion and Force again !

Not cover momentum yet. but that was great. Thank a lot learning physics.
8. ### Acceleartion and Force again !

OK, it was tricky ! And i was confused, how come the part a was so easy. Usually we use F=ma to find the acceleration when the problem involved with mass.
9. ### Acceleartion and Force again !

F_net (acting on the rocket) = 9000 (14.3) = 128700 N F_net (rocket) = F_net (gas) (From your hints if this two force were equal, then how come the rocket laugh forward) 128700 = 740 a a = 173.9 m/s2 Is this right ?
10. ### Acceleartion and Force again !

Problem 1 a) how come it is so easy ? b) got a little confuse, there only force of gravity is act on it.
11. ### Acceleartion and Force again !

#1 Is that hints for part b #2 F_apply = 30921.6 N #3 Is that mean I was going on the right track right ? F_apply = 262.9 N a) the box moves b) F_friction = .12 (815.7) = 97.9 N F_x = 310cos32 - 97.9 = 164.9 N F = ma 164.9 = 100a a = 1.65 m/s2 25 = (1/2)(1.65)t2 t = 5.5 s Am i doing right ?
12. ### Acceleartion and Force again !

#1 Ricky is on a rocket ship far from any planet or sun. The 900kg rocket fires its rockets for 3.5s sec and goes from 0m/s to 50 m/s.(a)What acceleration does the rocket undergo ?(b) If 160 kg of gas is expelled from the rocket. what is the gasses acceleration ? ------------------ vi = 50...
13. ### Acceleration coefficient

Yes ... thanks learningphysics
14. ### Acceleration coefficient

ok, I got this a = 3.3 m/s2
15. ### Acceleration coefficient

F (friction) = .25 time 7 = 1.75