Answer:
The answer is
<h2>4 hrs</h2>
Explanation:
To find the time taken we use the formula

where
d is the distance covered
v is the velocity
t is the time
From the question
d = 1200 miles
v = 300 mi/hr
We have

We have the final answer as
<h3>4 hrs</h3>
Hope this helps you
Answer:
TRUE
Explanation:
The answer is true.
Balance forces acting on a body will not change the motion of the body because the body experiences no net resultant force in one direction. When any body experiences equal forces with opposite directions, the net force or the resultant force experience by the body is zero.
In case of an unbalanced forces, there is a net force acting in one direction and so it causes the body to change in its state of motion in the direction of the net force.
Distance = speed x time. The total speed is 30 + 60 = 90km/h and the total time taken is 15 + 15 = 30 minutes. Therefore, you do 90 x 30 = 2700km
Answer = 2700km
Group 17 (VII) (halogens)
a) the number of protons is
more than the electrons
b) 
Explanation:
The net electric charge on the ball is

This electric charge is given by the algebraic sum of the charge of the protons and of the charge of the electrons.
The charge of one proton is:

While the charge of one electron is

So the net charge on the metal ball will be given by

where
is the number of protons
is the number of electrons
So we find:

This means that the number of protons is
more than the electrons.
b)
In this case, we want to make the ball neautral, so we have to remove a net charge of Q' such that the new charge is zero:

This implies that the charge that we must remove is

To do that (and to make the ball losing mass at the same time), we have to remove protons, since they have positive charge.
The number of protons that must be removed is:

The mass of one proton is

Therefore, the total mass that must be removed from the ball is
