They all travel at the same speed!
if you spoke english i could more than likely answer this for you thanks!
d) may be any of these , depending on the temperature
Let at temperature t , reading of both Celsius and Fahrenheit scale be same
using the formula of conversion
(F - 32) / 9 = C / 5
(t - 32) / 9 = t / 5
5t - 160 = 9t
t = - 40° Celsius .
For temperature above it , reading of Fahrenheit scale will be more . For temperature below it Fahrenheit scale will show lesser reading than Celsius
The work done is
Work Done = Change in Kinetic Energy (ΔKE)
In first 1 hour it travels 72 km
So, Velocity =
or, Initial Velocity (u) = 20 m/s
Similarly for the next hour it covers 90 km
or, Final Velocity (v) = 20 m/s
Work done = Change in Kinetic Energy (ΔKE)
Work done = ΔKE =
= = 281250 joule