I think Rebecca needs to be heavily medicated and not let lose in public if thats the kind of things she stands and obsessively compulsates about before getting into a friend's vehicle.
Umm, you do need the 9.8 m/s/s in the equation...You need it to find her weight in order to find her Normal force, because normal force is used to calculate friction.
In a general situation such as this, you definitely don't need the gravitational acceleration. Because it's included in finding the static friction in both the front and back seat, you can cancel it from both and still get proportional answers. Just saves a lot of time when you only need a greater/less than answer.
mass is irrelevant: bruised clavicle and broken nose in the front seat (unless the air-bag is off then strained muscles from the books being torn from her hands and no face injuries) in the front seat. at 88 lbs she is not tall enough to hit her head on th back of the seat (unless she is an anorexic fashion model then we need another discussion) so only bruises in the back seat.
This problem is unsolvable with the given information. You can't simply assume that if she sits in the front seat, her mass is distributed completely over the front wheels, and likewise with the back seat. Assuming the car is simply a mass sitting on two springs (which is a gross oversimplification), we would need to know the spring constants for the front and rear suspension. In order to reach a more accurate conclusion, we would have to integrate over the length of the car to find a rotational moment of inertia. Then, considering that the springs and the masses of Rebecca and all of her friends are causing torques on the car about the center of mass of the car, we would need to sum those torques and relate them to the summations of the forces on the springs in the up and down direction to find approximate compression distances for those springs. Finally, assuming the wheels do not compress, we could determine the forces caused by each spring in the suspension on the road, thus determining normal force on the road by the wheels.
"didn't really need the 9.8/s/s in this equation..ignored it, got 250N vs 280N. KISS lol"
See how far ignorance takes you...
"Umm, you do need the 9.8 m/s/s in the equation...You need it to find her weight in order to find her Normal force, because normal force is used to calculate friction."
Where do you see weight? I see mass, not weight. “…calculate friction?” They gave you the coefficients of friction for the respective locations, you are calculating FORCE as affected by friction and mass (acceleration being constant in this example). F is measured in SI units of the NEWTON.
To get a quick answer (historically the most reliable conclusions in science), you could ignore the acceleration due to gravity, but your answers would be without units. You accounted for the mass and factored in a coefficient, but ignored ACCELERATION. Hope F=ma isn't oversimplified to the point we stop using the "a."
Assuming the Force of Friction is Mu(s) * Normal Force, the Force of Friction would be 275 Newtons. She should sit in the back seat. No thumbs up because fuck Clickers.
32 comentarii:
I think Rebecca needs to be heavily medicated and not let lose in public if thats the kind of things she stands and obsessively compulsates about before getting into a friend's vehicle.
To the person who figured out the equation.
Amazing. You just won at life.
lol, "amazing"...
it's just physics, biach
I believe he was being sarcastic, unless you were being sarcastic, but yours was bad sarcasm if that's the case.
I like that we don't have to have an account to comment.
agreed
WOW YOU GUYS POST FROM THE FUTURE !! MY ISP IS WAY FASTER THAN I THOUGHT !
Anonymous, we are legion
Omg i love rebecca black! This makes my day!! Tehehehehehehe
Then suddenly, DICKS!!!! Thousands of them!!!!
didn't really need the 9.8/s/s in this equation..ignored it, got 250N vs 280N. KISS lol
Umm, you do need the 9.8 m/s/s in the equation...You need it to find her weight in order to find her Normal force, because normal force is used to calculate friction.
Sup gais
In a general situation such as this, you definitely don't need the gravitational acceleration. Because it's included in finding the static friction in both the front and back seat, you can cancel it from both and still get proportional answers. Just saves a lot of time when you only need a greater/less than answer.
That song might work with lyrics like that could nt be worse anyway
Hey anonymous... You know who you are..
Why don't you gravitationally accelerate my balls?
My life is now complete
Rebecca Black meme made it to Physics... 1st sign of the Apocalypse.
Also, "If she sits in the front seat she has to hold her friend's books."
Physics problems can now be solved with logic instead using good ol' formulas.
Again, we're boned.
lollolololol
What? NO! FRONT SEAT! If the thirteen-year-old in the driver's seat crashes the car, I want Rebecca to be as dead as possible.
mass is irrelevant: bruised clavicle and broken nose in the front seat (unless the air-bag is off then strained muscles from the books being torn from her hands and no face injuries) in the front seat. at 88 lbs she is not tall enough to hit her head on th back of the seat (unless she is an anorexic fashion model then we need another discussion) so only bruises in the back seat.
Sup physic nerds o/
This problem is unsolvable with the given information. You can't simply assume that if she sits in the front seat, her mass is distributed completely over the front wheels, and likewise with the back seat. Assuming the car is simply a mass sitting on two springs (which is a gross oversimplification), we would need to know the spring constants for the front and rear suspension. In order to reach a more accurate conclusion, we would have to integrate over the length of the car to find a rotational moment of inertia. Then, considering that the springs and the masses of Rebecca and all of her friends are causing torques on the car about the center of mass of the car, we would need to sum those torques and relate them to the summations of the forces on the springs in the up and down direction to find approximate compression distances for those springs. Finally, assuming the wheels do not compress, we could determine the forces caused by each spring in the suspension on the road, thus determining normal force on the road by the wheels.
Being a comparison max(a,b) you can leave out the constant (9.8m/s^2), because it has no effect on the final result.
"didn't really need the 9.8/s/s in this equation..ignored it, got 250N vs 280N. KISS lol"
See how far ignorance takes you...
"Umm, you do need the 9.8 m/s/s in the equation...You need it to find her weight in order to find her Normal force, because normal force is used to calculate friction."
Where do you see weight? I see mass, not weight. “…calculate friction?” They gave you the coefficients of friction for the respective locations, you are calculating FORCE as affected by friction and mass (acceleration being constant in this example). F is measured in SI units of the NEWTON.
To get a quick answer (historically the most reliable conclusions in science), you could ignore the acceleration due to gravity, but your answers would be without units. You accounted for the mass and factored in a coefficient, but ignored ACCELERATION. Hope F=ma isn't oversimplified to the point we stop using the "a."
anonymous, we are legion, we are many
Rofl, simple physics solved by trolls.
did anyone really need to comment on this? fail ALL
None of this was needed!!! Fail to ALL
dro is good
Assuming the Force of Friction is Mu(s) * Normal Force, the Force of Friction would be 275 Newtons. She should sit in the back seat. No thumbs up because fuck Clickers.
back seat.