Answer:
0.68 s
Explanation:
We are given that
Initial velocity of box=![u=13m/s](https://tex.z-dn.net/?f=u%3D13m%2Fs)
Final velocity of box=v=11.5 m/s
Distance=d=8.5 m
We have to find the time taken by box to slow by this amount.
We know that
![v^2-u^2=2as](https://tex.z-dn.net/?f=v%5E2-u%5E2%3D2as)
Substitute the values
![(11.5)^2-(13)^2=2a(8.5)](https://tex.z-dn.net/?f=%2811.5%29%5E2-%2813%29%5E2%3D2a%288.5%29)
![132.25-169=17a](https://tex.z-dn.net/?f=132.25-169%3D17a)
![-36.75=17a](https://tex.z-dn.net/?f=-36.75%3D17a)
![a=\frac{-36.75}{17}=-2.2m/s^2](https://tex.z-dn.net/?f=a%3D%5Cfrac%7B-36.75%7D%7B17%7D%3D-2.2m%2Fs%5E2)
We know that
Acceleration=![a=\frac{v-u}{t}](https://tex.z-dn.net/?f=a%3D%5Cfrac%7Bv-u%7D%7Bt%7D)
Substitute the values
![-2.2=\frac{11.5-13}{t}](https://tex.z-dn.net/?f=-2.2%3D%5Cfrac%7B11.5-13%7D%7Bt%7D)
![-2.2=\frac{-1.5}{t}](https://tex.z-dn.net/?f=-2.2%3D%5Cfrac%7B-1.5%7D%7Bt%7D)
![t=\frac{1.5}{2.2}=0.68 s](https://tex.z-dn.net/?f=t%3D%5Cfrac%7B1.5%7D%7B2.2%7D%3D0.68%20s)
Hence, the time taken by box to slow by this amount=0.68 s
The final velocity of the roller coaster is 58 m/s
Answer:
D.
Explanation:
Specifically, Special Relativity showed us that space and time are not independent of one another but can be mixed into each other and therefore must be considered as the same object, which we shall denote as space-time. The consequences of space/time mixing are: time dilation. and length contraction.