A sign whose weight is 95 lbs is held up by a chain.
(1) With what force does the chain need to be pulled up to keep the sign in place?
___________ lbs
(2) Jenna writes a mathematical description,
95 lbs + - 95 lbs = 0. What does the sign of each number represent? MULTIPLE CHOICE
a).that one is a chain force and one is gravity
b).how much force is added or subtracted to her hand
c).the direction in which each force is exerted
95LBS
AND
C
1)F=mg
F=95(9.8)
2) c
To find the force with which the chain needs to be pulled up to keep the sign in place, we need to understand the forces acting on the sign.
1) We know the weight of the sign is 95 lbs. Weight is the force exerted by gravity on an object, pulling it downwards. To keep the sign in place, the chain needs to provide an equal and opposite force in the upward direction. So, the force with which the chain needs to be pulled up to keep the sign in place is also 95 lbs.
2) Let's analyze Jenna's mathematical description: 95 lbs + - 95 lbs = 0. The sign "+/-" tells us the direction in which the forces are exerted.
a) The first option is incorrect because it suggests that one force is a chain force and the other is gravity. In reality, both forces are due to gravity, but one force is in the downward direction(95 lbs) and the other is in the upward direction(-95 lbs).
b) The second option is also incorrect because it implies that adding or subtracting forces is related to how much force is added or subtracted to Jenna's hand. However, in this case, the forces are related to the sign and the chain, not Jenna's hand.
c) The correct option is "c". The sign (+/-) represents the direction in which each force is exerted. The positive sign (+) indicates a force in the upward direction, while the negative sign (-) indicates a force in the downward direction.