Answer:
0.026
Explanation:
The force of friction acts in the direction perpendicular to the norm force of the surface on which the object rests, induced by gravity. The magnitude of the friction force is
(Friction) = (mass) x (gravitational acceleration g) x (coefficient of friction)
from which the coefficient of friction can be determined:
(coefficient of friction) = (Friction) / ((mass)x(g)) = 3 N / (12 kg * 9.8 m/s^2) = 0.026
Explanation:
you can see this example to undersranding the question
Answer:
Here is the answer. Hope this helps you!
Explanation:
Average velocity is the sum of initial and final velocity divided by 2. I t is the same as total Displacement divided by total time. Average velocity is calculated when the body is in non-uniform motion (also when total displacement and time is not given). The formula is as follows:
u + v/2 =
Average velocity = Average speed
during motion in a straight line. therefore, the above mentioned formula can be used for calculating average speed as well, when the direction is one and only the same, that is, during motion in a straight line. The S.I unit remains the same-
m/s.
Since velocity is vector, average VELOCITY is also vector. However, Average SPEED is scalar as speed is scalar. both can be equal only when the distance = displacement and when they are following the same direction of motion.
Answer:
a) t = 19.6 s, b) fr = 1.274 10⁴ N
Explanation:
This is a Newton's second law problem
Y Axis
for the cabin
N₁-W₁ = 0
N₁ = W₁
for the trailer
N₂- W₂ = 0
N₂ = W₂
X axis
for the cabin plus trailer, where friction is only in the cabin
fr = (m₁ + m₂) a
the friction force equation is
fr = μ N
we substitute
μ N₁ = (m₁ + m₂) a
μ m₁ g = (m₁ + m₂) a
a = μ g 
let's calculate
a = 0.65 9.8
a = 1,274 m / s²
a) to find the stopping distance we can use kinematics
Let's slow down the sI system
v₀ = 90 km / h (1000 m / 1km) (1h / 3600s) = 25 m / s
v = v₀ - a t
when it is stopped its speed is zero
0 = v₀ - at
t = v₀ / a
t = 25 / 1.274
t = 19.6 s
b) the friction force is
fr = 0.65 2000 9.8
fr = 1.274 10⁴ N
This is the braking force and also the forces that couple the cars.