Answer:
28.79%
Explanation:
Given
Design Speed, V = 120km/h = 33.33m/s
Radius, R = 300m
Side Friction, Fs = 0.09
Gravitational Constant = 9.8m/s²
Using the following formula, we'll solve the required rate of superelevation.
e + Fs = V²/gR where e = rate
e = V²/gR - Fs
e = (33.33)²/(9.8 * 300) - 0.09
e = 0.287853367346938
e = 28.79%
Hence, the required rate of superelevation for the curve is calculated as 28.79%
Jenny is traveling southward. In order to stop, she needs a northward acceleration.
A better way to say it:
Jenny is traveling southward in her bumper car, so the direction of her velocity is south. In order to reduce her velocity to zero, a velocity of equal magnitude but directed north must be added to it. Then the change in velocity is positive northward, and the change in velocity per unit time is acceleration.
We assign the variables: T as tension and x the angle of the string
The <span>centripetal acceleration is expressed as v²/r=4.87²/0.9 and (0.163x4.87²)/0.9 = </span><span>T+0.163gcosx, giving T=(0.163x4.87²)/0.9 – 0.163x9.8cosx.
</span>
<span>(1)At the bottom of the circle x=π and T=(0.163x4.87²)/0.9 – .163*9.8cosπ=5.893N. </span>
<span>(2)Here x=π/2 and T=(0.163x4.87²)/0.9 – 0.163x9.8cosπ/2=4.295N. </span>
<span>(3)Here x=0 and T=(0.163x4.87²)/0.9 – 0.163x9.8cos0=2.698N. </span>
<span>(4)We have T=(0.163v²)/0.9 – 0.163x9.8cosx.
</span><span>This minimum v is obtained when T=0 </span><span>and v verifies (0.163xv²)/0.9 – 0.163x9.8=0, resulting to v=2.970 m/s.</span>
The energy is 3.06 electronvolts, E = 3.06eV
1eV = 1.6 * 10^-19 J
3.06 eV = 3.06* 1.6 * 10^-19 J = 4.896 * 10^-19 J
