A block of mass 8.1 kg is pulled to the right by an applied force of 76.2 N. If the acceleration is 0.84 m/s^2, how much friction must be present?
To find the amount of friction, we need to use Newton's second law of motion, which states that the net force acting on an object is equal to the product of its mass and acceleration.
The applied force is 76.2 N, which is the force pulling the block to the right. The frictional force will act in the opposite direction, opposing the motion, so we can assume it to be negative.
The formula for calculating the net force is:
Net force = Applied force - Frictional force
Rearranging the formula to solve for the frictional force:
Frictional force = Applied force - Net force
Using the given values:
Applied force = 76.2 N
Net force = mass * acceleration
The mass of the block is given as 8.1 kg, and the acceleration is 0.84 m/s^2. So we can calculate the net force as:
Net force = 8.1 kg * 0.84 m/s^2
Now substituting the values back into the formula:
Frictional force = 76.2 N - (8.1 kg * 0.84 m/s^2)
Calculating the frictional force:
Frictional force = 76.2 - (6.804)
Therefore, the frictional force must be 69.396 N.