# physics

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.

1. 👍
2. 👎
3. 👁

## Similar Questions

1. ### physics

A 0.55 kg block of ice is sliding by you on a very slippery floor at 4 m/s. As it goes by, you give it a kick perpendicular to its path. Your foot is in contact with the ice block for 0.0025 seconds. The block eventually slides at

2. ### PHYSICS

A stone propelled from a catapult with a speed of 50m/s attains a height of 100m.Calculate:(a)the time of flight?

3. ### Physics

A child bounces in a harness suspended from a door frame by three elastic bands. (a) If each elastic band stretches 0.210 m while supporting a 7.35-kg child, what is the force constant for each elastic band? 114.33 N/m (b) What is

4. ### Math

13.8.33 Question Help If an object is propelled upward from a height of s feet at an initial velocity of v feet per​ second, then its height h after t seconds is given by the equation h=−16t squared + vt +​s, where h is in

1. ### math

four pencils are held together in a square by an elastic band if the pencils are of diameter 7mm what is the length of the band in this position

2. ### Physics

A boat propelled so as to travel with a speed of 0.5m/s in still water, moves directly (in a straight line) across a river that is 60m wide. The river flows with a speed of 0.30m/s. How long in seconds does it take the boat to

3. ### UTA

An object is thrown downward with an initial speed of 10 m/s from a height of 49 m above the ground. At the same instant, a second object is propelled vertically up from ground level with a speed of 29 m/s . At what height above

4. ### Math

If an object is propelled upward from ground level with initial velocity of 55 feet per second, it's height h in feet t seconds later is given by the equation H=-16t^2+55t. after how many seconds does the object hit ground?

1. ### honors physics

A 3.2 kg block is hanging stationary from the end of a vertical spring that is attached to the ceiling. The elastic potential energy of this spring/mass sytem is 2.1 J. What is the elastic potential energy of the system when the

2. ### algebra

If a rocket is propelled upward from ground level, it's height in meters after t seconds is given by h=-9.8t^2+88.2t. During what interval of time will the rocket be higher than 137.2m? h=9.8t^2+ 88.2t I divided both sides by -9.8

3. ### Algebra 2

A large asteroid crashed into a moon of a planet, causing several boulders from the moon to be propelled into space toward the planet. Astronomers were able to measure the speed of one of the projectiles. the distance (in feet)

4. ### physics

Identify the force that propels a rocket. 1)The rocket is propelled by the reaction force of the exhaust gasses bouncing off the air molecules outside the rocket. 2)The rocket is propelled because the action force of the rocket on