# phyics help nedded

In the figure below, three ballot boxes are connected by cords, one of which wraps over a pulley having negligible friction on its axle and negligible mass. The masses are mA = 24.0 kg, mB = 40.0 kg, mC = 30.0 kg.

(a) When the assembly is released from rest, what is the tension in the cord that connects boxes B and C?
N

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

1. 👍 2
2. 👎 1
3. 👁 5,003
1. (a) m(A)a=T1
m(B)a=m(B)g-T1+T2
m(C)a=m(C)g-T2
a{m(A) + m(B)+m(C)} = T1+ m(B)g-T1+T2 + m(C)g-T2 =g{ m(B)+m(C)}
a= g{ m(B)+m(C)}/{ m(A) + m(B)+m(C)} =9.8(40+30)/(24+40+30) =7.3 m/s²

T1 =m(A)a=24•7.3=175.2 N
T2 = m(C)(g-a) = 30•(9.8-7.3)= 75 N

(b) s=at²/2 = 7.3•0.25²/2 = 0.228 m

1. 👍 2
2. 👎 4
2. So how can we state the appropriate answer to part (a)...?

1. 👍 0
2. 👎 0
3. the answer to (a) is T2

1. 👍 0
2. 👎 2

## Similar Questions

1. ### TEAS 6 MOMETRIX

mandy can buy 4 container of yogurt and 3 boxes of crackers for \$9.55. she can buy 2 containers of yogurt and 2 boxes of crackers for \$5.90. How much does one box of crackers cost? Answer: \$2.25 Equations 4x + 3y = \$9.55 2x + 2y =

2. ### Math

1. Make a sketch of 5 rectangular open boxes such that a. the height of the boxes are the same, b. The boxes can hold 249cm^3, 504 cm^3,810 cm^3 and 468 cm^3 respectively. 2. Solve each quadratic equation by completing the square

3. ### physics help needed very urgent !!!

The figure shows four penguins that are being playfully pulled along very slippery (frictionless) ice by a curator. The masses of three penguins and the tension in two of the cords are m1 = 10.5 kg, m3 = 14.7 kg, m4 = 22.05 kg, T2

4. ### Math

A Boy Scout has 3 meters of rope. He cuts the rope into cords 3/5m long. How many cords will he make?

1. ### Physics

A 3.00 - µF and a 4.00 - µF capacitor are connected in series, and this combination is connected in parallel with a 2.00 - µF capacitor (see the figure ). What is the net capacitance? 3.00 - µF 4.00 - µF 2.00 - µF 26.0 V

2. ### Physics

Suppose two boxes on a frictionless table are connected by a heavy cord of mass 1.0 kg. Calculate the acceleration (magnitude) of each box and the tension (magnitude) at each end of the cored, using the free-body diagrams shown in

3. ### Physics

Two boxes are connected by a light string that passes over a light, frictionless pulley. One box rests on a frictionless ramp that rises at 30° above the horizontal (see the Figure below), and the system is released from rest.

4. ### AP Physics

Two 10 kilogram boxes are connected by a massless frictionless pulley. The boxes remain st rest with the one on the right hanging vertically and the one on the left 2.0 meters from the bottom of an inclined plane that makes an

1. ### physics

Boxes A and B are connected to each end of a light vertical rope. A constant upward force F = 80.0 N is applied to box A. Starting from rest, box B descends 12.0 m in 4.00 s. The tension in the rope connecting the two boxes is

2. ### physics

Two boxes are connected by a weightless cord running over a very light frictionless pulley as shown in the figure. Box A, of mass 8.0 kg, is initially at rest on the top of the table. The coefficient of kinetic friction between

3. ### math

Nathan and Steven stacked boxes on a shelf. Nathan lifted 13 boxes and Steven lifted 15 boxes. The boxes that Nathan lifted each weighed 12 lb more than the boxes Steven lifted. Which expression represents the total number of

4. ### physics

A puck on a horizontal, frictionless surface is attached to a string that wraps around a pole of finite radius, as shown in the figure . As the puck moves along the spiral path, does its speed increase, decrease, or stay the same?