a lawnmower with a mass of 12 kg is being pushed by a force of 150n horizontally and 40 n down. if the kinetic coefficient of friction between the grass is 0.9, find the force of friction on the lawnmower.
Please explain this as well, I am getting an answer but I don't know.
Friction is mu Fn. The normal force in this case comes from two sources. mg and 40N down. The 150N is not needed for the question.
To find the force of friction on the lawnmower, we first need to calculate the normal force acting on it. The normal force is the perpendicular force exerted by the surface (in this case, the grass) to support the weight of the lawnmower.
The weight of the lawnmower can be calculated using the formula:
Weight = mass × acceleration due to gravity
Given that the mass of the lawnmower is 12 kg, and the acceleration due to gravity is approximately 9.8 m/s², we can calculate the weight:
Weight = 12 kg × 9.8 m/s²
Now, we can calculate the normal force. Since the lawnmower is on a flat surface, the normal force is equal to the weight:
Normal Force = Weight
Next, we need to calculate the frictional force. The frictional force can be determined using the formula:
Frictional Force = coefficient of friction × Normal Force
Given that the coefficient of friction is 0.9 and we have already calculated the normal force, we can now find the frictional force:
Frictional Force = 0.9 × Normal Force
Finally, substitute the value of the normal force into the equation:
Frictional Force = 0.9 × Weight
To summarize, the force of friction on the lawnmower can be found by calculating the normal force (which is equal to the weight of the lawnmower) and then multiplying it by the coefficient of friction. In this case, using the given information, we have determined that the force of friction is 0.9 times the weight of the lawnmower.
To find the force of friction on the lawnmower, you need to calculate the sum of the horizontal and vertical forces acting on the lawnmower. Let's break it down step by step:
1. Calculate the horizontal forces:
The horizontal force being applied on the lawnmower is 150 N. There are no other horizontal forces acting on it. So, the net horizontal force is 150 N.
2. Calculate the vertical forces:
The vertical force being applied on the lawnmower is 40 N downwards. Also, there is a force acting in the opposite direction of motion due to friction. To calculate this force of friction, we need to use the kinetic coefficient of friction (µk) and the normal force (N).
The normal force is equal to the weight of the lawnmower, which is the product of its mass (m) and the acceleration due to gravity (g). In this case, m = 12 kg, and g = 9.8 m/s^2. So, N = m * g = 12 kg * 9.8 m/s^2 = 117.6 N.
3. Calculate the force of friction:
The force of friction is given by the equation: Friction = µk * N.
In this case, the kinetic coefficient of friction (µk) is 0.9, and the normal force (N) is 117.6 N (as calculated in step 2).
So, the force of friction = 0.9 * 117.6 N.
Calculating this value, the force of friction on the lawnmower is approximately 105.84 N.
Therefore, the force of friction on the lawnmower is approximately 105.84 N.