On the change in potential energy
Let x mph be the speed of the ship in still water.
Against the current, the net speed is, (x-1.9) mph.
Time, t= distance, d/ Speed, v => 9= 113.4/(x-1.9) => 9(x-1.9) = 113.4 => x-1.9 = 113.4/9 => x = 12.6+1.9 = 14.5 mph
Moving with the current, the net speed of the ship = 14.5+1.9 =16.4 mph
Time take, t = d/v = 113.4/16.4 = 6.915 hours
Answer:
Explanation:
a)
v² = u² + 2 a s
v = 9 m/s
u = 4 m/s
s = 50 m
9² = 4² + 2 x a x 50
a = 0.65 m /s²
Acceleration is 0.65 m /s²
b )
time elapsed before velocity changed from 4 m/s to 9 m/s with acceleration of .65 m /s ²
(v - u ) / t = a
(v - u ) / a = t
(9 - 4 ) / .65 = t
t = 7.7
time when passing the first sign will be 7.7 s earlier .
Reading of time indicator = 45 - 7.7
= 37.3 seconds.
If the statistical analysis shows that the significance level is below the cut off value they have set (either 0.05 or 0.01) they reject the null hypothesis and accept the alternative hypothesis
A microwave has more energy than radio but less than visible light