In pushing a heavy box across the floor, is the force you need to apply to start the box moving greater than, less than, or the
1 answer:
Answer:
Explanation:
Force needed to apply start the box is greater than the force needed to keep it moving because static friction is greater than the kinetic friction .
A threshold force is needed to move the box and when box started to move kinetic friction comes into play.
Friction force is directly related to the weight of the box as the friction force is
coefficient of friction time Normal reaction .
And Normal reaction is equal to the weight of box if no force is applied.
You might be interested in
Answer:
For the complete question provided in explanation, if the elevator moves upward, then the apparent weight will be 1035 N. While for downward motion the apparent weight will be 435 N.
Explanation:
The question is incomplete. The complete question contains a velocity graph provided in the attachment. This is the velocity graph for an elevator having a passenger of 75 kg.
From the slope of graph it is clear that acceleration at t = 1 sec is given as:
Acceleration = a = (4-0)m/s / (1-0)s = 4 m/s^2
Now, there are two cases:
1- Elevator moving up
2- Elevator moving down
For upward motion:
Apparent Weight = m(g + a)
Apparent Weight = (75 kg)(9.8 + 4)m/s^2
<u>Apparent Weight = 1035 N</u>
For downward motion:
Apparent Weight = m(g - a)
Apparent Weight = (75 kg)(9.8 - 4)m/s^2
<u>Apparent Weight = 435 N</u>
