A 1000-kg barge is being towed by means of two horizontal cables. One cable is pulling with a force of 80.0 N in a direction 30.0° west of north. In what direction should the second cable pull so that the barge will accelerate northward, if the force exerted by the cable is 120 N? Assume that the water exerts no appreciable frictional drag on the barge.

To solve this problem, we need to break down the forces acting on the barge and determine the net force in the northward direction. Then, we can find the direction of the second cable's pull.

Let's analyze the forces acting on the barge:
1. The force of the first cable pulling at 80.0 N in a direction 30.0° west of north.

To determine the net force in the northward direction, we can use vector addition. The north component of the force exerted by the first cable can be calculated as follows:

North component of force 1 = 80.0 N * cos(30.0°)

Now, let's calculate the north component of the second cable's force to determine the direction it must pull:

North component of force 2 = Net force in the northward direction - North component of force 1
= 120 N - (80.0 N * cos(30.0°))

Finally, calculate the angle of the second cable's pull using the north component of force 2:

Angle of second cable's pull = arccos(North component of force 2 / 120 N)

Note: This assumes the angle is measured from the eastward direction.

By following these steps, you should be able to calculate the direction in which the second cable needs to pull the barge to accelerate northward.

To solve this problem, we'll use vector addition and trigonometry. Let's break down the given information:

1. The first cable is pulling with a force of 80.0 N at an angle of 30.0° west of north.
2. The second cable needs to be pulled in a direction so that the barge accelerates northward with a force of 120 N.

Now, let's find the components of the two forces:

1. The first force can be broken down into its northward and westward components. The northward component can be found by multiplying the force by the cosine of the angle: northward force = 80.0 N × cos(30.0°).
2. The second force can be broken down into its northward and westward components. Since we want the barge to accelerate northward, the northward force is 120 N.

Next, we'll use vector addition to find the resultant force:

1. Add the northward components of the two forces together: northward component of resultant force = northward component of the first force + northward component of the second force.
2. Since the barge should accelerate northward, the northward component of the resultant force should be positive.

Finally, we'll find the direction of the second cable:

1. Calculate the angle that the second cable should have with the north direction using inverse cosine: angle = arccos(northward component of the resultant force / magnitude of the resultant force).

Plug in the values and solve for the angle:

northward component of the first force = 80.0 N × cos(30.0°)
northward component of the second force = 120 N
northward component of the resultant force = northward component of the first force + northward component of the second force
magnitude of the resultant force = sqrt((northward component of the resultant force)^2 + (westward component of the resultant force)^2)
angle = arccos(northward component of the resultant force / magnitude of the resultant force)

After solving these equations, you should find the direction in which the second cable should pull for the barge to accelerate northward.

2nd Cable Direction = 30o E. of N.