physics, confusions

[izzahzainab]

1. two objects having "same temperature" can have different amount of heat. true???

2. friction acts on MOVING bodies???? and resistance acts on stationary objects?? true?

3. why is work a scalar quantity?

4. what happens to voltage across a component when its resistance increases? i think ,,,,decreased current ....will decrease voltage. but it can also increase because the potential DIFFERENCE has increased .. :0

5. celsius and centigrade are same?

6. what effect does a magnetic field have on a single isolated charge?

thanks in advance

 

[izzahzainab]

1. when do we use fleming's left hand and fleming's RIGHT hand rule?

 

[scouserlfc]

We use Flemings Left Hand rule when there is a permenant Magent involved when no we use the right hand one. Got it.

 

[scouserlfc]

for 4 voltage and current are directly proportional and therefore whatever happens to current happens to voltage or vice versa.

5.Yup they are same,

3.Work is a Scalar quantity as there is only Magnitude in it no North south or directions like in forces are there.

 

[izzahzainab]

but work has a direction, doesn't it, cuz work is only done when force is applied , and the object moves in the direction of force

 

[scouserlfc]

NO SORRY I SOME WHAT FORGOT THE DEF OF SCALRS A SCALAR QUALITY SAYS THAT A quantity which does not depend on direction is called a scalar quantity.SO WORK IS ONE/

 

[SalmanPakRocks]

Scalar has no magintude while vector has it !!

 

[scouserlfc]

YEAH SCALAR DOES NOT DEPEND ON DIRECTIONS WHILE VECTORS LIKE SPEED AND FORCES DO/

 

[SalmanPakRocks]

Exactly !!

 

[scouserlfc]

NOW DO 1,2 AND 6

 

[OakMoon!]

1. Yes they can. Materials of different mass and of different heat capacity retain different amounts of heat even when at the same temperature.
2. Moving objects offer resistance too. Its called inertia. Which is for both moving and stationary object. Friction is basically for moving objects. Even a moving object resists change in motion until an external force acts on it.
3.Work done=Force*Displacement.. Vector*Vector=Scalar. As simple as that.
Fleming's left hand rule is used when you have to find the direction of the force on the wire, that is the thumb. While, fleming's right hand rule is used when the direction of magnetic field and the direction of force is given and you have to find the direction of the induced current i.e. the middle finger. Remember, always use right hand for middle finger and the left hand for thumbs up.

 

[izzahzainab]

thanku so much! its all clear now

 

[OakMoon!]

4.When the resistance across a component increases the voltage drops, given that current remains constant. This is due to ohms law that states V=IR. Increase in resistance increases voltage.
5. Yes, Celcius and Centigrade are the same. Different terms are used in different countries.
6. A magnetic field will deflect the isolated charge according to the fleming's left hand rule. Tell me if you need the detail for it.

 

[OakMoon!]

You are welcome.