chapter 10 - force and motion

Question 1

what is elastic deformation?

Answer 1

when an object can go back to its original shape and size when deforming forces are removed

Question 2

what is inelastic deformation?

Answer 2

when an object does not go back to its original shape and size when deforming forces are removed

Question 3

how do you find the spring constant from a force-extension graph of a spring?

Answer 3

find the gradient of the straight line section

Question 4

what forces are balanced when an object travels at a steady speed?

Answer 4

resistive forces = driving force

Question 5

what is the acceleration of an object proportional to? (newtons second law)

Answer 5

the force acting on it

Question 6

what is the acceleration of an object inversely proportional to? (newtons second law)

Answer 6

the objects mass

Question 7

what does intertia mean?

Answer 7

the tendency of an object to remain in a steady state - at rest or in uniform motion

Question 8

what is the acceleration of a free-falling object due to gravity?

Answer 8

approximately 9.8 m/s^2

Question 9

name for the steady speed a falling object reaches when the resistive force is equal to its weight?

Answer 9

terminal velocity

Question 10

general name for the frictional forces an object experiences when moving through a fluid? (liquid or gas)

Answer 10

drag

Question 11

what direction does the drag on an object always act?

Answer 11

in the direction of the opposite to which its moving

Question 12

what happens to the drag on an object as its speed increases?

Answer 12

the drag increases

Question 13

what can be done to reduce the drag on an object?

Answer 13

streamlining

Question 14

name given to the distance a vehicle travels to safely come to a stop after the driver has spotted a hazard?

Answer 14

stopping distance

Question 15

what is thinking distance?

Answer 15

the distance a vehicle travels during the drivers reaction time

Question 16

what is the braking distance?

Answer 16

the distance the vehicle travels once the brakes have been applied

Question 17

what is the relationshio between stopping distance, thinking distance and braking distance?

Answer 17

stopping distance = thinking distance + braking distance

Question 18

does the speed of a vehicle have a bigger effect on braking distance or thinking distance?

Answer 18

braking distance

Question 19

factors that affect the braking distance of a vehicle?

Answer 19

• speed
• road conditions
• condition of tires and brakes