8 newton's law of motion

Question 1

friction

Answer 1

force opposing the motion of a surface that moves or tries to move across another surface

Question 2

weight

Answer 2

the force of gravity acting on an object

W=mg

Question 3

gradational field strength

Answer 3

force of gravity per unit mass on a small object

9.81

Question 4

intertia

Answer 4

resistance of an object to change of its motion

Question 5

terminal speed

Answer 5

the maximum speed reached by an object when the drag force on it is equal and opposite to the force causing the motion of the object

Question 6

drag force

Answer 6

the force of fluid resistance on an object moving through a fluid

Question 7

motive force

Answer 7

the force that drives a vehicle

Question 8

thinking distance

Answer 8

the distance travelled by a vehicle in the time it takes the driver to react

Question 9

braking distance

Answer 9

the distance travelled by a vehicle in the time taken to stop it

Question 10

stopping distance

Answer 10

thinking distance + braking distance

Question 11

newtons second law

Answer 11

F=ma

Question 12

newtons first law

Answer 12

objects either stay at rest or move with constant velocity unless acted on by a force

Question 13

resultant force

Answer 13

F1 - F2 = ma

Question 14

rocket problems

Answer 14

T = mg + ma

Question 15

pull problems

Answer 15

Mg -mg = (M+m)a

Question 16

drag force depends on

Answer 16

shape of the object
speed
viscosity of the fluid

Question 17

impact time

Answer 17

t = 2s/ u+v

Question 18

impact force

Answer 18

F=ma

Question 19

vehicle bumpers

Answer 19

lower impact speed- increase the impact time
impact force is reduced
high speed= damage

Question 20

crumple zones

Answer 20

give way in a front end impact

impact time is increased and impact force reduced

Question 21

seat belt

Answer 21

slows you down gradually

Question 22

collapsible steering wheel

Answer 22

if the driver makes contact with the steering wheel, the impact force is lessened as a result of the steering wheel collapsing in the impact

Question 23

airbags

Answer 23

reduces the force on a person, because the airbag acts a as a cushion and increase the impact time on the person. force of impact is spread over the contact area is pressure is reduced