Answer:
Explanation:
There are only two forces causing motion involved. They oppose each other. You know this because there is no acceleration of the sled: you see only a velocity.
The formula when friction is involved is
Fnet = T - mu*Normal
mu is the frictional coefficient
The normal is the downward force caused by the mass of the sled being pulled down by the gravitational constant.
The tension is brought about by the dog pulling in the opposite direction to the frictional force.
The frictional force, oddly, acts in a horizontal direction even though the normal is vertical. It does this because friction always opposes motion.
Since there is no acceleration, the net force = 0
N= m * a_g
m = 1.2 kg
a_g = 9.8
N = 1.2 * 9.8
N = 11.76
The frictional force = mu*Normal Force.
Ff = N * mu
N = 11.76
mu = 0.2
Ff = 0.2 * 11.76
Ff = 2.35
As stated The frictional force and the Tension are equal but in opposite directions
T = 2.35