If a 68kg object is being pulled across the hard floor with a horizontal force of 400N...
a. What would the acceleration of the object be if it was on a frictionless floor?
b. if there were friction, what would the force of friction be if it was pulled at a constant velocity?
c. If it wasn't at a constant velocity, but instead accelerating at 3.2m/s^2, what would the force of friction be acting on the object?
d. What would the coefficient be when the object accelerates at 3.2m/s^2
Thanks!
a. Try using Newton's second law. (F = ma)
b. Ditto. acceleration (a) equals zero. What does that tell you about the net force?
c. Again, use Newton's second law
d. Use the definition of the coefficient of (kinetic) friction, together with the friction force and the weight.
a. To find the acceleration of the object on a frictionless floor, you can use Newton's second law of motion which states that the net force acting on an object is equal to the mass of the object multiplied by its acceleration (F = m * a).
In this case, the force acting on the object is the horizontal force of 400N. The mass of the object is 68 kg.
So, the equation becomes: 400N = 68kg * a
Rearranging the equation to solve for acceleration (a), we have: a = 400N / 68kg
Calculating this expression, the acceleration of the object would be approximately 5.88 m/s^2.
b. If there is friction and the object is pulled at a constant velocity, we know that the force of friction is equal in magnitude and opposite in direction to the applied force. Therefore, the force of friction would also be 400N.
c. If the object is accelerating at 3.2 m/s^2, we can use the same formula, F = m * a, to find the force of friction. In this case, the force acting on the object is still 400N, and the mass of the object is 68 kg. The only difference is that the acceleration is now 3.2 m/s^2.
So, the equation becomes: 400N = 68kg * 3.2 m/s^2
Rearranging the equation to solve for the force of friction, we have: force of friction = 400N - (68kg * 3.2 m/s^2)
Calculating this expression, the force of friction on the object would be approximately 187.6N.
d. To calculate the coefficient of friction, we need to know the force of friction and the normal force. The normal force is the force exerted by a surface to support the weight of an object resting on it. On a flat horizontal floor, the normal force is equal to the weight of the object.
In this case, the weight of the object can be calculated as the mass multiplied by the acceleration due to gravity (9.8 m/s^2). So, the weight of the object would be: 68 kg * 9.8 m/s^2.
The coefficient of friction (μ) can be found by dividing the force of friction by the normal force: μ = (force of friction) / (normal force).
Plugging in the values we have, the coefficient of friction would be approximately: (187.6N) / (68 kg * 9.8 m/s^2).