A. True
if cold air is replacing warm air it is a cold front and vice versa.
Answer:
(a) increase
Explanation:
On a line graph; we have the x-axis to the positive side and the negative side .In a positive x-axis direction, the force is usually positive, vice versa the negative side as well.
The change in the potential energy of a charge field-system can be given as:

where;
q = positive test charge
E = Electric field
ds = displacement between thee charge positions
θ = Angle between the electric field and the displacement.
Given that:
Charge of the particle = -q
displacement = (60.0 -20.0)cm = 40.0 cm
θ = 0
Replacing our values in the above equation, we have:


Since the potential energy of the system is positive, therefor the electric potential energy also increases.
Answer:
Acceleration: 
Final velocity: 
Explanation:
To calculate the acceleration, you start from the formula:

Thus:

Now that you have the accelration, you can use the this formula to calculate the final speed:

Thus:

Answer:
2.6645m
Explanation:
applying motion equations we can find the answer,

Let assume ,
u = starting speed(velocity)
v = Final speed (velocity)
s = distance traveled
a = acceleration
by the time of reaching the highest point subjected to the gravity , the speed should be equal to zero
we consider the motion upwards , in this case the gravitational acceleration should be negative in upwards (assume g =10 m/s2 downwards)
that is,
