: A 50kg wooden crate rests on a horizontal concrete floor. The coefficient of friction is u=0.7. What is the magnitude of the frictional force?
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To calculate the magnitude of the frictional force, we need to use the formula:
frictional force = coefficient of friction * normal force
The normal force is the force exerted by the surface perpendicular to the object, which in this case is the weight of the crate. The weight can be calculated using the formula:
weight = mass * gravity
Where the mass of the crate is given as 50 kg and the acceleration due to gravity is approximately 9.8 m/s².
So, let's calculate the weight first:
weight = 50 kg * 9.8 m/s² = 490 N
Next, we can calculate the frictional force using the coefficient of friction (u) and the normal force:
frictional force = 0.7 * 490 N = 343 N
Therefore, the magnitude of the frictional force is 343 N.