Help - finding what slope means

  • Thread starter Thread starter an_mui
  • Start date Start date
  • Tags Tags
    Means Slope
AI Thread Summary
To create a straight line graph with the fifth root of time (t^1/5) on the y-axis, the student should plot the tenth root of distance (d^1/10) on the x-axis. This transformation results in a linear relationship where the slope of the line represents a constant related to the acceleration of the cart. The equation d = (1/2)at^2 indicates that if acceleration is constant, the relationship between distance and time will be parabolic. The slope derived from the linear graph will provide insights into the cart's acceleration. Understanding these relationships is crucial for analyzing motion in physics.
an_mui
Messages
47
Reaction score
0
urgent help - finding what slope means

Suppose a student is given position-time data for a cart which was known to have an initial velocity of zero. if the student plots the fifth root of time (t^1/5) on the y axis, what variable should he plot on the x-axis so that the resulting graph is a straight line? how is the slope of the line related to the acceleration of the cart?


d = \frac{1}{2}at^2
d^\frac{1}{10} = (\frac{1}{2}a)^\frac{1}{10} t^\frac{1}{5}

this is what I've done so far... can anyone give me some hints as to what to do next? thank you i need to know the answer in 1 hour =(
 
Physics news on Phys.org
Normally if one was given position - time data, one would plot position (displacement from some reference) on the y-axis (a dependent variable) and time on the x-axis (independent variable).

The slope would then be the speed or magnitude of velocity, and it would be a straight line if there were no acceleration.

If there were an acceleration or deceleration the slope would not be straight. The second derivative of the curve would give the acceleration. If acceleration were constant, distance would be a parabolic function of time.

To get a straight line in a plot, one would have to take d = \frac{1}{2}at^2 and take the log or ln of the expression to get
ln d = ln\frac{a}{2} + 2 ln t and this assumes a is constant.

Think about y = t1/5

x = ?, and one wants to find dy/dx = d(t1/5)/d(?)

to get a straight line \frac{d^2y}{dx^2} = 0
 
an_mui said:
Suppose a student is given position-time data for a cart which was known to have an initial velocity of zero. if the student plots the fifth root of time (t^1/5) on the y axis, what variable should he plot on the x-axis so that the resulting graph is a straight line? how is the slope of the line related to the acceleration of the cart?
d = \frac{1}{2}at^2
d^\frac{1}{10} = (\frac{1}{2}a)^\frac{1}{10} t^\frac{1}{5}
this is what I've done so far... can anyone give me some hints as to what to do next? thank you i need to know the answer in 1 hour =(
You've got the answer right there : call t^{1/5} = y. Then rearranging the equation gives

y = d^{1/10}/(a/2)^{1/10} = k \cdot d^{1/10}

So, if you make the x-axis contain values of d^{1/10} you are done. You will then have a line of the form y = kx, where the slope of the line, k, is ... ?
 
Last edited:
TL;DR Summary: I came across this question from a Sri Lankan A-level textbook. Question - An ice cube with a length of 10 cm is immersed in water at 0 °C. An observer observes the ice cube from the water, and it seems to be 7.75 cm long. If the refractive index of water is 4/3, find the height of the ice cube immersed in the water. I could not understand how the apparent height of the ice cube in the water depends on the height of the ice cube immersed in the water. Does anyone have an...
Thread 'Variable mass system : water sprayed into a moving container'
Starting with the mass considerations #m(t)# is mass of water #M_{c}# mass of container and #M(t)# mass of total system $$M(t) = M_{C} + m(t)$$ $$\Rightarrow \frac{dM(t)}{dt} = \frac{dm(t)}{dt}$$ $$P_i = Mv + u \, dm$$ $$P_f = (M + dm)(v + dv)$$ $$\Delta P = M \, dv + (v - u) \, dm$$ $$F = \frac{dP}{dt} = M \frac{dv}{dt} + (v - u) \frac{dm}{dt}$$ $$F = u \frac{dm}{dt} = \rho A u^2$$ from conservation of momentum , the cannon recoils with the same force which it applies. $$\quad \frac{dm}{dt}...
Back
Top