Explanation:
after 5 seconds, the velocity is (5s)(3m/s²) = 15m/s
The displacement after 5s is
x=vo + (1/2)at²
x = 0 + (1/2)(3m/s²)(5s)(5s)
x= 37.5 m
The added weight of the sand puts more downward pressure on the wheels contacting the rails, which would cause the trains speed to decrease.
Answer: W =
J
Explanation: Since the potassium ion is at the outside membrane of a cell and the potential here is lower than the potential inside the cell, the transport will need work to happen.
The work to transport an ion from a lower potential side to a higher potential side is calculated by

q is charge;
ΔV is the potential difference;
Potassium ion has +1 charge, which means:
p =
C
To determine work in joules, potential has to be in Volts, so:

Then, work is


To move a potassium ion from the exterior to the interior of the cell, it is required
J of energy.