Hey All
This was a HSC Multiple choice from 2006
5) Two identical boxes are resting on a truck tray. The tray is gradually tilted. The load in one box is twice as heavy as the load in the other
Which statement is true
a) The lightly loaded box would slide before the heaviliy loaded box
b) The heavily loaded box would slide before the lightly loaded box
c) Both boxes would slide at the same time regardless of their load
d) Both boxes would have the same normal reaction regardless of their load
The Answer is (c) and I chose (a) as my answer.
The reason I chose (a) was because F=mn
F = frictional force
m = coeffient of friction
n = normal reaction
The coefficent of friction would be the same for the boxes but one of the boxes would have a larger normal reaction and hence have a larger frictional force because coefficient of friction x normal reaction are proportional to frictional force. So if the heavily loaded box has a larger reaction force then it has a large frictional force so shouldnt it slide first. ?
Then I tried another way. Tanm = Angle of sliding.
So the angle of the incline would stay constant for both boxes so theoretically they should slide at the same time?
I am not unsure about this question. Can anybody explain the concept behind it becaue I understand all the friction, power, incline questions and calculations but this one has stumped me.
This was a HSC Multiple choice from 2006
5) Two identical boxes are resting on a truck tray. The tray is gradually tilted. The load in one box is twice as heavy as the load in the other
Which statement is true
a) The lightly loaded box would slide before the heaviliy loaded box
b) The heavily loaded box would slide before the lightly loaded box
c) Both boxes would slide at the same time regardless of their load
d) Both boxes would have the same normal reaction regardless of their load
The Answer is (c) and I chose (a) as my answer.
The reason I chose (a) was because F=mn
F = frictional force
m = coeffient of friction
n = normal reaction
The coefficent of friction would be the same for the boxes but one of the boxes would have a larger normal reaction and hence have a larger frictional force because coefficient of friction x normal reaction are proportional to frictional force. So if the heavily loaded box has a larger reaction force then it has a large frictional force so shouldnt it slide first. ?
Then I tried another way. Tanm = Angle of sliding.
So the angle of the incline would stay constant for both boxes so theoretically they should slide at the same time?
I am not unsure about this question. Can anybody explain the concept behind it becaue I understand all the friction, power, incline questions and calculations but this one has stumped me.
