Physics people? Please help me!
Senior Member
Joined: Jun 2002
Posts: 934
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From: Little Rock, AR
Originally Posted by athena
Consider a force of 66.5N, pulling 3 blocks of identical masses, where each mass is 0.8kg, along a rough horizontal surface. The coefficient of kinetic friction between the blocks and the surface is given by 0.2. The acceleration of the blocks is a. The acceleration of gravity is 9.8m/s^2. Find the acceleration a. Answer in units of m/s^2.
Can someone help me out.
Can someone help me out.
The fact that she pulled up a 3-year old post to ask a physics question or the fact that people are actually asking physics questions in the general discussion section of F150online.com.
Maybe we should add a homework section for all of the high-schoolers and college students on here.
Certified Goat Breeder
Joined: Feb 1999
Posts: 6,182
Likes: 19
From: the moral high ground
How do you determine the magnitude and direction of the net force acting on the object?
An illegal alien is running 12.6 mph in Mexico when he encounters President Bush's 9 foot wall at the border.
His leap slows his forward speed to 4.75 mph.
Forward momentum increases his air speed to 15.25 mph and an inertia forward distance of 7.7 feet into the Continental US.
He resumes his 12.6 mph running speed.
Question: Is the total overall delay of 8.9 seconds equal to $2.2 Billion dollars?
An illegal alien is running 12.6 mph in Mexico when he encounters President Bush's 9 foot wall at the border.
His leap slows his forward speed to 4.75 mph.
Forward momentum increases his air speed to 15.25 mph and an inertia forward distance of 7.7 feet into the Continental US.
He resumes his 12.6 mph running speed.
Question: Is the total overall delay of 8.9 seconds equal to $2.2 Billion dollars?
Senior Member
Joined: Jun 2005
Posts: 258
Likes: 0
From: Pratt, KS
Originally Posted by athena
Consider a force of 66.5N, pulling 3 blocks of identical masses, where each mass is 0.8kg, along a rough horizontal surface. The coefficient of kinetic friction between the blocks and the surface is given by 0.2. The acceleration of the blocks is a. The acceleration of gravity is 9.8m/s^2. Find the acceleration a. Answer in units of m/s^2.
Can someone help me out.
Can someone help me out.
I think this is correct, I'm assuming you just add all the masses together and assume as one mass? It's been some time since my Engineering Physics I class.
To find the magnitude of force being applied to resist the effect of the 66.5N force, take the sum of the mass of the three blocks (3*0.8kg=2.4kg) and multiply that by the gravitational constant to find the "normal" force applied between the blocks and the surface (2.4kg*9.8m/s^2=23.52N). Now take the "normal" force times the coeffcient of friction (23.52N*0.2=4.7N). This 4.7N is the force resisting the 66.5N force resulting in a net force of 61.8N.
For the horizontal acceleration of the blocks, simply divide the force by the mass of the blocks (61.8N/2.5kg=24.72m/s^2).
Senior Member
Joined: Jan 2003
Posts: 2,079
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From: Pikesville, MD
Originally Posted by Raoul
...
Question: Is the total overall delay of 8.9 seconds equal to $2.2 Billion dollars?
Question: Is the total overall delay of 8.9 seconds equal to $2.2 Billion dollars?
3 million people delayed 8.9 seconds is 26.7 million seconds or 7417 hours saved a year. Figuring they make an average of 7.00 an hour that is $51,919 saved each year.
A 2.2 billion dollar investment to save $52,000...sign me up. Normally our ROI on gov't programs are 0%. Woo Hoooo Government
By the way...Pat Buchanan was on the Daily show last night...Jon asked Pat...what do you think about a 12' foot fence on the border? Pat said "what they only make 6' ladders in Mexico?" This isn't exact but lord they were funny.