Physics HELP!
posted by Jennifer .
A 650 N boy and a 490 N girl sit on a 150 N porch swing that is 1.70 m long. If the swing is supported by a chain at each end, what is the tension in each chain when the boy sits .75 m from one end and the girl .5 m from the other end?

The sum of the two chain tesnions is
T1 + T2 = 650 + 490 = 1140 N
Take moments about the chain nearest to the girl and set the sum equal to zero. Call the cable nearest the boy "1". The boy is 0.95 m from the girl's end, "2".
T1*1.7 0.95*650  0.5*490 = 0
Solve for T1. Then use T1 + T2 = 1140 N to solve for T2. 
Shouldn't we consider the weight of the swing as well?

Yes. Good thinking. I overlooked it

So then assuming the swing is uniform, do I have:
T1 + T2 = 650 + 490 + 150 = 1290 N
Then,
T1*1.7 0.95*650  0.5*490 .85*150 = 0
Solve for T1 and then use the first equation to solve for T2? 
Yes. :)

how is this equation right? when i multiplied all those numbers to get T1 i got a huge number...to plug it back in for T2 i would get a negative number...
Respond to this Question
Similar Questions

physics
A girl 36 kg occupies a seat of a swing that this subject by two chains 20 m in length each. If someone drops the girl from an 8 m position below the highest of the swing. What strength exercises it on the girl when she passes through … 
physics
A girl 36 kg occupies a seat of a swing that this subject by two chains 20 m in length each. If someone drops the girl from an 8 m position below the highest of the swing. What strength exercises it on the girl when she passes through … 
physics
Child weighs 29 kg on a swing supported by two chains. Another child pulls swing back to the chains to make 30 degree angle with the vertical. What force is exerted by each chain 
ap Physics
AP PROBLEM CHILD ON A SWING AN ADULT EXERTS A HORIZONTAL FORCE ON A SWING THAT IS SUSPENDED BY A ROPE OF LENGTH L, HOLDING IT AN AN ANGLE q WITH THE VERTICAL. THE CHILD IN THE WING HAS WEIGHT W AND DIMENSIONS THAT ARE NEGLIGIBLE COMPARED … 
physics
Two parakeets sit on a swing with their combined center of mass 15.0 cm below the pivot. At what frequency do they swing? 
science
A uniform plank of a seesaw is 5 meter long and supported at its centre.a boy weighing 40kgf sits at a distance 1.5meter from one end of the seesaw.where must a girl weighing 25kgf sit on the other end of the seesaw so as to balance … 
AP Physics
A 35kg child sits in a swing supported by 2 chains, each 3.7 m long. If the tension in each chain at the lowest point is 274 N find the child's speed at the lowest point. (Neglect the mass of the seat). I'm not sure what equations … 
physics
calculate the mass of an object attached at the end of the rope 7.5m long suspended from a fixed support and made to swing.suppose the speed of the object at its lowest point of the swing is 3m/s and the tension in the rope at the … 
physics
a grandfather clock is designed to have a pendulum which swings a mass at the end of the chain in a horizontal circular motion. the pendulum is designed to swing 7 degrees off of the vertical. the chain is 1.50 meters long and the … 
Physics Please
A boy on a swing is pulled to a position 2.34 m off the ground and released. At the fastest and lowest point of the swing the boy is 0.50 m off the ground and travelling 3 m/s. The percent efficiency of this swing system is?