Forces

Question 1

define force

Answer 1

anything that causes a body to accelerate

Question 2

what are balanced forces

Answer 2

when there is no net force; cause an object to stay stationary or move at a constant velocity

Question 3

what are unbalanced forces

Answer 3

cause an object to accelerate or change velocity

Question 4

when drawing arrows ..

Answer 4

the larger force with a thicker arrow , think of balance and unbalanced

Question 5

define friction

Answer 5

a force that opposes motion.

Question 6

3 advantages of friction

Answer 6

less slipping, make brakes work, slow down hailstones reducing damage

Question 7

disadvantages of friction 3

Answer 7

slows down moving bodies and wastes energy
causes wearing of surfaces
casues excessive heating and noise

Question 8

4 ways friction can be reduced?

Answer 8

oiling
streamlining (making objects moving through air more aerodynamic)
smoothing surfaces
using wheels between surfaces

Question 9

define gravity

Answer 9

a measure of the force of attraction between two bodies with mass

Question 10

define weight

Answer 10

the measure of the force of gravity acting on an object

Question 11

formula for weight on different planets

Answer 11

weight = mass (kg) x g value ((use N unit for weight)

Question 12

what is the g value

Answer 12

acceleration due to gravity; m s-2

Question 13

investigate the relationship between the extension of a spiral spring and the force applied to it

Answer 13

retort stand, with a spiral spring attahced to the top and metre stick at the bottom, running alongside the retort stand vertically. pointer at the bottom of the spiral spring, note length. Add a slotted weight to the bottom of the spring, note the length and caluclate extension. Draw extension vs applied force graph. CONCLUSION: Hooke’s law.

Question 14

Hooke’s Law says..

Answer 14

The extension of a spiral spring is directly proportional to the applied force