Question

A woman pushes an oak chest across an oak floor at a constant speed of 0.450 m/s. The chest has a mass of 40.0 kg, and the coefficient of kinetic is 0.620. What is the force exerted by the woman?

A. 243 N
B. 11.1 N
C. 3.81 N
D. 29.0 N

(If there's work please show the best you can)

Answer 1

The force exerted by the woman is the same as the frictional force, which is calculated as the product of the coefficient of kinetic friction (0.620) and the normal force (mass times gravity for the chest, 40.0 kg × 9.8 m/s² = 392 N). The frictional force, and hence the force exerted, is 243 N.

Step-by-step explanation:

The force exerted by the woman can be found by calculating the frictional force, which is the product of the coefficient of kinetic friction and the normal force. Since the chest moves at constant speed, the force exerted by the woman equals the frictional force.

First, find the normal force, which is the weight of the chest (mass times the acceleration due to gravity, g = 9.8 m/s²):

Normal Force = Mass × g = 40.0 kg × 9.8 m/s² = 392 N

Now, calculate the frictional force:

Frictional Force = Coefficient of Kinetic Friction × Normal Force = 0.620 × 392 N = 242.64 N

Thus, the force exerted by the woman is 243 N (rounded to three significant digits), which corresponds to option A.

Answer 2

A. 243 N

Step-by-step explanation:

Friction is the force that opposes the relative motion between systems that are in contact.

This friction force that opposes the motion of the oak chest across the oak surface will be equal and opposite to that exerted by the woman.

First find the normal force which is the force that would point directly upwards to support weight of the block.

Normal force, N= mg where m is the mass of the chest and g is the acceleration due to gravity.

Given m=40 kg and g=9.80 m/s²

N force=40×9.80 =392N

Then find the force of friction which is given by the formula;

F=μN where μ is friction coefficient for the oak chest and N is the normal force on the chest

Given μ=0.620 and N force = 392 N then it will be;

F=0.620× 392 =243.04 N

Answer : 243 N