Answer:
#1
Explanation:
On a train you are sitting so not in motion but to someone outside the train you are in motion with the train
Answer:
the maximum possible coefficient performance is 13.7
Explanation:
inside temperature,
= 61 F = 289.26 K
outside temperature,
= 99 F = 310.37 K
coefficient of performance, COP (real) = 3.2
according to Carnot's theorem, the coefficient of performance is
= 
where
is cold temperature
is hot temperature
thus,
= 
= 13.7
Answer:
394.26 m
Explanation:
t = Time taken
u = Initial velocity
v = Final velocity
s = Displacement
a = Acceleration due to gravity = 9.8 m/s²



Total time taken by the stone to reach the ground is 4.49+4.49 = 8.97 seconds

The times are equal so,

The height is 394.26 m
Answer:
The difference between the velocity graph made walking at a steady rate means that its the same value in time, that means there's no slope on the graph, so its acceleration is 0
On the other hand, if the velocity is increasing with time, the slope of the graph becomes positive, which means that the acceleration of the particle is positive.