Answer:
The acceleration would be positive, pointing to the right.
Explanation:
The acceleration tells us how velocity changes every second. If the train stops, this means its velocity must go from a non-zero value to zero.
To reduce velocity, acceleration must point to the opposite direction. Since velocity is negative, acceleration must be positive.
Answer:
There is much more friction on the rough surface than there is on the smooth surface.
Explanation:
Answer:
Ep = 3924 [J]
Explanation:
To calculate this value we must use the definition of potential energy which tells us that it is the product of mass by the acceleration of gravity by height.

where:
Ep = potential energy [J] (units of Joules)
m = mass = 40 [kg]
g = gravity acceleration = 9.81 [m/s²]
h = elevation = 10 [m]
![E_{p} =40*9.81*10\\E_{p} = 3924 [J]](https://tex.z-dn.net/?f=E_%7Bp%7D%20%3D40%2A9.81%2A10%5C%5CE_%7Bp%7D%20%3D%203924%20%5BJ%5D)
Answer: Im not entirly sure but I think It's D all the above. I think all but B because I never really heard of that but if you look in our history I think that happen im not sure I would wait untill you know that somone knows for sure.
Explanation:
Answer:
protons (+ charge) & neutrons (neutral charge)
however protons has a positive charge so it determined what atom it is.