Valleys are one of the most common landforms on the Earth and they are formed through erosion or the gradual wearing down of the land by wind and water. In river valleys for example, the river acts as an erosional agent by grinding down the rock or soil and creating a valley
Answer:
Explanation:
Given that
Mass , m = 25 kg
We know that when body is in rest condition then static friction force act on the body and when body is in motion the kinetic friction force act on the body .That is why these two forces are given as follows
Static friction force ,fs= 165 N
Kinetic friction force ,fk = 127 N
If the body is moving with constant velocity ,it means that acceleration of that body is zero and all the forces are balanced.
Lets take coefficient of kinetic friction = μk
The kinetic friction is given as follows
fk = μk m g
Now by putting the values
127 = μk x 25 x 9.81


Therefore the value of coefficient of kinetic friction will be 0.51
The answer of this question would be D
Hi there
Definition of heat
the quality of being hot; high temperature.
Answer:
The magnitude of the electrostatic force decreases by a factor 9
Explanation:
The electrostatic force between two charges is given by:

where
k is the Coulomb's constant
q1 and q2 are the two charges
d is the distance between the two charges
We see that the magnitude of the force is inversely proportional to the square of the distance. If the distance is increased to 3d: d' = 3d, the new electrostatic force would be:

So, the electrostatic force decreases by a factor 9.