a brick has mass of 1.2 kg. a force of 5.4 N is needed to move the brick along the floor with a constant velocity. what is the coefficiant of friction?
constant velocity means no net accelerating force, which means the pushing force of 5.4N is equal to the opposing force, friction.
Frictionforce=mu*mg
solve for mu.
A car moves at 12 m/s and coast up a hill with a uniform acceleration of -1.6 m/s^2..What is its displacment after 6 sec.? What is its displacment after 9 sec.?
To find the coefficient of friction, we need to use the formula:
Coefficient of friction = Force of friction / Normal force
First, let's find the force of friction:
Force of friction = Force required to move the brick = 5.4 N
Now, let's calculate the normal force:
Normal force = Mass × gravitational acceleration
Given:
Mass of the brick (m) = 1.2 kg
Gravitational acceleration (g) = 9.8 m/s^2
Normal force = 1.2 kg × 9.8 m/s^2 = 11.76 N
Now, we can find the coefficient of friction:
Coefficient of friction = Force of friction / Normal force
Coefficient of friction = 5.4 N / 11.76 N
Coefficient of friction ≈ 0.459
To find the coefficient of friction, we can use the equation:
Friction force = coefficient of friction × normal force
In this case, the friction force is given by the applied force needed to move the brick along the floor with a constant velocity, which is 5.4 N. The normal force is the force exerted by the floor on the brick, which is equal to the weight of the brick (mass × acceleration due to gravity).
Let's break down the steps to find the coefficient of friction:
Step 1: Calculate the normal force
The weight of the brick can be calculated using the formula:
Weight = mass × acceleration due to gravity
Given:
Mass of the brick (m) = 1.2 kg
Acceleration due to gravity (g) = 9.8 m/s²
Weight = 1.2 kg × 9.8 m/s²
Step 2: Calculate the coefficient of friction
Since we know that the applied force needed to move the brick along the floor is equal to the friction force, as stated earlier, we can plug in the values in the friction force equation:
Friction force = coefficient of friction × normal force
5.4 N = coefficient of friction × (mass × acceleration due to gravity)
Coefficient of friction = 5.4 N / (mass × acceleration due to gravity)
Now you can substitute the values:
Coefficient of friction = 5.4 N / (1.2 kg × 9.8 m/s²)
Evaluating this equation will give you the coefficient of friction.