# physics

posted by
****chocolatekisses** on
.

Three boxes are connected by cords, one of which (mA) wraps over a pulley having negligible friction on its axle and negligible mass and two boxes (mB & mC) are hanging. The masses are mA = 22.0 kg, mB = 40.0 kg, mC = 16.0 kg.

-When the assembly is released from rest, what is the tension in the cord that connects boxes B and C?

-How far (in meters) does box A move in the first 0.250 s (assuming it does not reach the pulley)?

Write the force equation clockwise being positive.

Ma*g-Mb*g-Mc*g=totalmass*acceleration.

where total mass is the sum of the three masses. Solve for acceleration.

Tension that connects to B is the same as the tension that is connected to A.

Ma*g-Tension=totalmass*acceleration

displacement= 1/2 acceleration*time^2