Upstream speed = S - 1
Downstream speed = S + 1
Average speed = total distance / total time
Average speed = (S - 1) + (S + 1) / 2
= S
S = 6 miles / 4 hours
S = 1.5 miles per hour
Answer:
<h2>15.25 N</h2>
Explanation:
A force of
is acting on a wagon along the road. The wagon weights
. Acceleration of the wagon is given as
.
Consider the block as the system, the forces acting are Frictional force, Gravitational force, Normal reaction and External force applied by us.
Gravitational Force and Normal Reaction cancel out each other.
Net External Force = Mass of system/wagon
Acceleration of wagon

has a negative sign because it opposes the motion of the wagon.
∴ Frictional Force = 15.25 N
The said development of the cell where the three cell layers help out do it is called as Gastrulation. The three layers - called as ectoderm, endoderm, and mesoderm - tend to form as this happens. This is a process that's present in all living things except sponges.
Planets orbit the sun in the paths which are known as elliptical orbit. Each planet has its own orbit around the sun and direction in which all the planets orbit around the sun are the same. These orbits were well explained by the astronomer Kepler. The gravity of the Sun keeps the planets in their orbits. They stay in their orbits because there is no other force in the Solar System which can stop them.