chapt 3 (force and pressure)

Question 1

what are the types of forces? (4+3)

Answer 1

Contact forces:
- Friction
- AR
- Tension
- Normal force

Non contact forces:
- Gravitational force
- Electrostatic force
- Magnetic force

Question 2

definition of weight? (1) why is weight related to gravitational force? (1) how to measure weight? (1) and scalar or vector? (1)

Answer 2

Gravitational force acting on object that has mass.
Bcs weight varies on the gravitational pull of different atmospheres. w=mg.
Use spring balance.
Vector quantity.

Question 3

Definition of mass? (1) how to get mass? (2) scalar or vector? (1)

Answer 3

Measure of the amount of matter in a body.
Use electronic & beam balance.
Scalar quantity.

Question 4

density formula? (1)

Answer 4

d= m/v

Question 5

when forces are acting PERPENDICULARLY per unit area gives? (1) formula?(1)

Answer 5

gives PRESSURE.

P= F/A