A toy consists of three cars that are pulled in tandem on small frictionless rollers. The cars have masses m1=3.1 kg, m2=2.4 kg, and m3=1.2 kg. If they are pulled to the right with a horizontal force P=6.5 N, find (a) the acceleration of the system, (b) the force exerted by the second car on the third car, and (c) the force exerted by the first car on the second car.
If the answers are (a) 0.97 m/s^2 (b) 1.2 N (c) 3.5 N how would I get there?
~thanks.
If the answers are (a) 0.97 m/s^2 (b) 1.2 N (c) 3.5 N how would I get there?
~thanks.
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a) a (system ) = Force / mass ( system ) = 6.5 / ( 3.1 + 2.4 + 1.2 )
= 6.5 / 6.7 = 0.97015 = 0.97 m/s/s
b) Force on third car is m . a = 1.2 . 0.97 = 1.164 = 1.2 N
c) Force on the second car = m . a = ( 2.4 + 1.2 ) . 0.97 = 3.4925 = 3.5 N
( the second car has the third car attached to it - that is why the mass has to be recorded as 3.6 kg )
= 6.5 / 6.7 = 0.97015 = 0.97 m/s/s
b) Force on third car is m . a = 1.2 . 0.97 = 1.164 = 1.2 N
c) Force on the second car = m . a = ( 2.4 + 1.2 ) . 0.97 = 3.4925 = 3.5 N
( the second car has the third car attached to it - that is why the mass has to be recorded as 3.6 kg )