I thought I knew how to set these up by looking at some of the other posts and our notes, but I couldn't get an answer. Can anybody help me with these?
1. Number 1 you're using the formula F=ma. The most likely reason that you're getting it wrong is that you're using the wrong units. Initially you have to adjust your answer to get it in the right units. By following the formula you're probably getting the correct answer, you're just not in the units it's asking for.
5. Ok so it gives you the mass and the angle and the tension of the rope. F=ma is the formula you're going to use here, but before you can use it to find the acceleration, you have to find the force that's missing, which is the force of gravity against the incline. To find this you need the weight of the wagon which is then multiplied by the vertical component of the angle (draw a diagram, it really helps). The weight of the wagon multiplied by the vertical component of the angle (sin theta) gives you the force of gravity (negative). Now you can do F=ma where you combine the forces (remember the force of gravity is negative) and solve for acceleration. Now that you have acceleration I would suggest using the V^2 formula to solve for V.
15. Again F=ma is the way to get the answer. Sum of all forces=(mass)(acceleration). The two forces here are the force of gravity and the force on the scale itself. So Fscale-Fg=ma Add Fg to both sides so you get :Fscale=Fg+ma To get the acceleration you have to divide the uniform acceleration it gives you by the amount of time (Since it's deceleration the final value will be negative).
Now you should have Fscale=Fg+ma where ma will give a negative value. Solve for Fscale.
2 comments:
1. Number 1 you're using the formula F=ma. The most likely reason that you're getting it wrong is that you're using the wrong units. Initially you have to adjust your answer to get it in the right units. By following the formula you're probably getting the correct answer, you're just not in the units it's asking for.
5. Ok so it gives you the mass and the angle and the tension of the rope. F=ma is the formula you're going to use here, but before you can use it to find the acceleration, you have to find the force that's missing, which is the force of gravity against the incline. To find this you need the weight of the wagon which is then multiplied by the vertical component of the angle (draw a diagram, it really helps). The weight of the wagon multiplied by the vertical component of the angle (sin theta) gives you the force of gravity (negative). Now you can do F=ma where you combine the forces (remember the force of gravity is negative) and solve for acceleration. Now that you have acceleration I would suggest using the V^2 formula to solve for V.
15. Again F=ma is the way to get the answer. Sum of all forces=(mass)(acceleration). The two forces here are the force of gravity and the force on the scale itself. So Fscale-Fg=ma Add Fg to both sides so you get :Fscale=Fg+ma
To get the acceleration you have to divide the uniform acceleration it gives you by the amount of time (Since it's deceleration the final value will be negative).
Now you should have Fscale=Fg+ma where ma will give a negative value. Solve for Fscale.
Thank you so much. I owe you one. (or a couple)
Post a Comment