Physics (Net Forces/Newton's laws)

[austin1250]

Alright well I have 2 questions I am stuck on.

first is:

Four forces act on a hot-air balloon, shown from the side in the figure below. Find the magnitude and direction of the resultant force on the balloon if F1 = 4600 N, F2 = 1250 N, F3 = 1000 N, and F4 = 4200 N.


F1 is pointing up, F4 is pointing down, F2 is pointing left and F3 is pointing right.

It asks for the force in N and at what degree clockwise from F2.

I got the force to be 300 N northward, and 250 N to the lef (west). I don't get how to get the Degree(direction) clockwise from F2. Any help?



And the other problem is:
An 1750 kg car is moving to the right at a constant speed of 1.92 m/s.

(a) What is the net force on the car?
_______ N to the right
(b) What would be the net force on the car if it were moving to the left?
_______ N to the left

I don't really know what to do here. i just used F=MA but it was wrong. i don't think 1.92 m/s can be used since it isn't acceleration but i don't really know what to do. any help?

 

[PhanthomJay]

Alright well I have 2 questions I am stuck on.

first is:

Four forces act on a hot-air balloon, shown from the side in the figure below. Find the magnitude and direction of the resultant force on the balloon if F1 = 4600 N, F2 = 1250 N, F3 = 1000 N, and F4 = 4200 N.


F1 is pointing up, F4 is pointing down, F2 is pointing left and F3 is pointing right.

It asks for the force in N and at what degree clockwise from F2.

I got the force to be 300 N 4600-4200 = 400northward, and 250 N to the lef (west). I don't get how to get the Degree(direction) clockwise from F2. Any help?

You have the components of the resultant, can you find the magnitude of the resultant using the Pythagorean Theorem? Can you find the angle of the resultant using the trig properties of a right triangle?

And the other problem is:
An 1750 kg car is moving to the right at a constant speed of 1.92 m/s.

(a) What is the net force on the car?
_______ N to the right
(b) What would be the net force on the car if it were moving to the left?
_______ N to the left

I don't really know what to do here. i just used F=MA but it was wrong. i don't think 1.92 m/s can be used since it isn't acceleration but i don't really know what to do. any help?

You must use the acceleration. What is the car's acceleration if it is moving at constant speed?

 

[thomate1]

Hello! I am happy to assist you with these questions on physics and net forces. Let's take a look at each one individually:

1. For the first question about the hot-air balloon, we can use Newton's Second Law to find the resultant force on the balloon. This law states that the net force acting on an object is equal to its mass multiplied by its acceleration. In this case, the balloon is not accelerating, so the net force is equal to zero. Therefore, we can set up an equation where the sum of all the forces acting on the balloon (F1 + F2 + F3 + F4) is equal to zero. This can also be represented as ΣF = 0.

Next, we can break down each force into its components (horizontal and vertical) and use trigonometry to find the magnitude and direction of the resultant force. For example, F1 can be broken down into a vertical component (F1v) and a horizontal component (F1h). The vertical component will be equal to the force itself (4600 N) since it is already pointing in the vertical direction. The horizontal component can be found using the cosine function, where F1h = F1 x cos(θ) and θ is the angle between F1 and the horizontal direction. Similarly, we can find the horizontal and vertical components for the other forces (F2, F3, and F4).

Once we have all the components, we can add them together to find the resultant force in both the horizontal and vertical directions. The magnitude of the resultant force can be found using the Pythagorean theorem, where the square of the resultant force is equal to the sum of the squares of the horizontal and vertical components. Finally, we can use trigonometry again to find the direction of the resultant force, which will be the angle between the resultant force and the horizontal direction.

2. For the second question about the moving car, we can use the same approach as above. Since the car is moving at a constant speed, we know that the net force on the car is equal to zero. This means that the forces acting on the car are balanced and there is no acceleration.

However, if the car were to move in the opposite direction (to the left), the net force would no longer be zero. In this case, the net force would be equal to the force of friction acting in the opposite direction of