find the average of a block being propelled propelled by an elastic band.
We know it is uniform acceleration.
my attempt on this problem
Measure the force applied of elastic band with a newton scale. The more you strecth the farther the distance the block will travel after you let it go. In my case my Fa was 6N. i proposed this idea to my teacher but he said the as the elastic band destreches after you let it go the force become 6,5,4,3,2. I am wondering if this is a correct way of finding the Fa. Then i would perfrom three trials to find the average.To find the average i would perform trials 2 times and divide them by three to find the average of d,t,forceapplied. i would find the distance,and time and assume V1 is 0. Can i assume V1 is 0 since it is in rest? my teacher looked puzzled i and i sure v1 is not 0. so then using v1,d,t, i would find v2 when it reaches the final velocity. then i would find the Acceleration acting on the block by using v1,v2,d,t. then i would find force normal by entering this fn=Mag
which would be mass x acceleration acting on block x acceleration due to gravity. i don't know how to go about finding force of friction because i can use this equation. FF=uFn.
One more question
can i find Fnet=Ma since i am going to find acceleration. will finding Fnet help me out?
thanks. Any suggestions ar welcome. Sir/Mam if u have any links on average force of friction please include them. i am been trying to tackle this problem forever.
What makes you think it is uniform acceleration. To get uniform acceleration, your force has to be constant, and as your teacher pointed out, force is not constant.
I have no idea what you are trying to do. Is it to measure the force of friction?
IF so, did I answer this? Ket me go back: Assume the rubberband is elastic (it is near so). THe potential energy stored in it is 1/2 k x^2 You can measure k pretty easily (force=kx, use a spring scale to measure the force at some x).
Now, set the potential energy of the rubber band (stretched x cm) equal to the work done on friction.
1/2 kx^2= Fricionforceaverage*(x+ distance) where distance is the amount the block traveled beyond the unstretched point, and x is the distance it traveled with the rubber band).
Solve for the average friction force.
This setup, done three times, will give reasonable results.
To find the average of a block being propelled by an elastic band with uniform acceleration, you first need to understand that the force applied by the elastic band is not constant. As your teacher pointed out, the force varies as the band stretches and releases.
To measure the force applied by the elastic band, you can use a Newton scale. By stretching the band to different lengths and measuring the force at each length, you can obtain a series of force values such as 6N, 5N, 4N, 3N, 2N. However, keep in mind that these values do not represent a constant force but rather a changing force.
To proceed with finding the average, you need to perform multiple trials. For example, let's say you perform three trials. In each trial, measure the distance traveled by the block (after being released by the elastic band) and the time it takes for the block to travel that distance. Repeat this process for all three trials.
To find the average distance (d), average time (t), and average force applied (F), sum up the values you obtained in each trial and divide by three. This will give you the average values.
Now, assuming the initial velocity (v1) of the block is 0 since it starts from rest, you can use the average distance (d) and average time (t) to find the final velocity (v2). Knowing v1, v2, d, and t, you can calculate the acceleration (a) of the block using the formula: a = (v2 - v1) / t.
To find the net force acting on the block (Fnet), you can use Newton's second law, Fnet = ma. Since you have calculated the acceleration (a) in the previous step, you can substitute it into the formula with the mass (m) of the block to determine the net force.
Regarding the force of friction (Ff), you mentioned the equation FF = uFn, which is accurate. This equation represents the force of friction (Ff) as the product of the coefficient of friction (u) and the normal force (Fn) acting on the block. The normal force can be calculated as Fn = mass x acceleration acting on the block x acceleration due to gravity.
To find the average force of friction, you can use the setup mentioned earlier. Set the potential energy stored in the elastic band (1/2 k x^2) equal to the work done against friction. Solve for the average friction force (Ff). Repeat this setup for each trial and then calculate the average friction force.
In summary, to find the average of a block being propelled by an elastic band with uniform acceleration, you need to measure the force applied by the band, perform multiple trials to obtain average distance, time, and force applied, calculate the acceleration, net force, and average force of friction using relevant equations and formulas.