Sorry for this long post..but normal force is a MCAT favorite, right? So here it goes.
Consider a rollercoaster cart moving around the inner circle of a loop. Ignoring the effect of friction, the normal force values are plotted as the cart moves 360 degrees. As expected the normal force value is maximum at the bottom of the cart and minimum at the top of the loop.
Q: When you adjust the normal force values due to the effect by friction, the normal force value on the cart would:
A: remain the same
B. increase everywhere
C. decrease everywhere in the loop
D. decrease everywhere or increase everywhere.
The answer is C. And qualitatively it makes sense since friction will slow down the moving cart. And a lower cart velocity will mean a lower centripetal Force.
However, quantitatively, there is no direct quantitative relationship between friction and normal force. And yet we know it makes a difference in the normal force value. Can we say the same about gravitational force?
At 90 degrees, for example, the centripetal force directly equals the normal force in a loop. Does excluding or including the force of gravity affect the normal force value however? Basically, if a physicsist was trying to determine the necessary centripetal force needed to keep a roller coaster in check at 90-degree point at the loop, would gravity affect his calculation even though it's perpendicular to the centripetal force?
Consider a rollercoaster cart moving around the inner circle of a loop. Ignoring the effect of friction, the normal force values are plotted as the cart moves 360 degrees. As expected the normal force value is maximum at the bottom of the cart and minimum at the top of the loop.
Q: When you adjust the normal force values due to the effect by friction, the normal force value on the cart would:
A: remain the same
B. increase everywhere
C. decrease everywhere in the loop
D. decrease everywhere or increase everywhere.
The answer is C. And qualitatively it makes sense since friction will slow down the moving cart. And a lower cart velocity will mean a lower centripetal Force.
However, quantitatively, there is no direct quantitative relationship between friction and normal force. And yet we know it makes a difference in the normal force value. Can we say the same about gravitational force?
At 90 degrees, for example, the centripetal force directly equals the normal force in a loop. Does excluding or including the force of gravity affect the normal force value however? Basically, if a physicsist was trying to determine the necessary centripetal force needed to keep a roller coaster in check at 90-degree point at the loop, would gravity affect his calculation even though it's perpendicular to the centripetal force?
