Answer:
helium-4 (90%) or tritium (7%).
Explanation:
hope it helped u buddy
Answer:
Action - Pulling up the train.
Reaction - Friction on the locomotive
Explanation:
Locomotive is pulling the train upwards ,
Which is the action force applied by the locomotive,
As a reaction locomotive will be pulled by the train which is the reaction of pulling
Now, considering it as a action on locomotive , friction force will act on it as a reaction upwards which will result to move it upwards.
For train action is pulling up by locomotive and reaction will be friction acting on it downwards.
1) 3 miles/Hour
The speed is defined as the distance covered divided by the time taken:

where
d = 1.5 mi is the distance
t = 0.5 h is the time taken
Substituting,

2) 1.34 m/s south
Velocity, instead, is a vector, so it has both a magnitude and a direction. We have:
is the displacement in meters
is the time taken in seconds
Substituting,

And the direction of the velocity is the same as the displacement, so it is south.
A)
At time = .003 hr
B)
90* (3*10^-3) = .27km
C)
.005 hr
D)
Car A = 150 * (.005) = .75km
Car B = (90 * (.005) = .45 km
E)
Car A = 150 * (0.008) = 1.2 km
Car B = 90 * (0.008) = 0.72 km
Car A is ahead