8.2 Using F=MA *Further problems

Question 1

when an object is acted on y two unequal forces what way does the object accelerate

Answer 1

in the direction of the larger force

Question 2

how would you find the acceleration of 2 unequal forces

Answer 2

F1-F2=ma
(resultant force)

Question 3

how do you find the acceleration of a car towing a trailer and the acceleration of the trailer

Answer 3

F - T = Ma

force on the car - tension in the tow bar

T = ma

combining the equations gives

F = (M+m)a

Question 4

rocket thrust =

Answer 4

T= mg + ma

therefore rocket thrust must overcome the weight of the rocket for it to take off

Question 5

what equation is used for lift problems

Answer 5

T-mg =ma

Question 6

if a lift is moving at constant velocity what is a and t

Answer 6

a = 0
t = mg

Question 7

if the list is moving up and accelerating what is a and t

Answer 7

a>0
t = mg+ma >mg

Question 8

if the lift is moving up and declarating what is a and t

Answer 8

a<0 t=mg+ma<mg

Question 9

if the lift is moving downwards and accelerating what is a and t

Answer 9

a<0
t = mg+ma<mg

Question 10

if the lift is moving down and accelerating what is a and t

Answer 10

a>0
t=mg+ma>mg

Question 11

when is the tension in the cable less than the weight

Answer 11

if the lift is moving up and decelerating
if the lift is moving down and accelerating

Question 12

when is tension in the cable greater than the weight

Answer 12

if the lift is moving up and accelerating

if the lift is moving down and decelerating