# Maths mechanics question

Watch
Announcements
#1
A box of mass 80kg is pulled along a horizontal floor by a rope. The rope is pulled with a force of 100N and the rope is inclined at (20 °) to the horizontal
1. Explain Briefly why the box cannot be equilibrium if the floor is smooth. (In Fact the floor is not smooth and the box is in equilibrium )
2. Calculate The Frictional Force Between The box and the floor and also the normal reaction of the floor on the box The Maximum value of the frictional force between the box and the floor is 120N and the box is now pulled along the floor with the rope always inclined 20° to the horizontal
3. Calculate the force with which the rope must be pulled for the box to move at a constant speed.
4. Calculate the acceleration of the box if the rope is pulled with a force of 140N

0
5 years ago
#2
A box of mass 80kg is pulled along a horizontal floor by a rope. The rope is pulled with a force of 100N and the rope is inclined at (20 °) to the horizontal
1. Explain Briefly why the box cannot be equilibrium if the floor is smooth. (In Fact the floor is not smooth and the box is in equilibrium )
2. Calculate The Frictional Force Between The box and the floor and also the normal reaction of the floor on the box The Maximum value of the frictional force between the box and the floor is 120N and the box is now pulled along the floor with the rope always inclined 20° to the horizontal
3. Calculate the force with which the rope must be pulled for the box to move at a constant speed.
4. Calculate the acceleration of the box if the rope is pulled with a force of 140N

3) Use the fact that the force pulling the rope must equal the frictional force for the box to move at constant velocity. From F=ma, resultant force must be 0 if a=0.

4) Again: F=ma. Find the resultant force, you're given the mass.
0
5 years ago
#3
I think they are a case of F=ma
0
5 years ago
#4
(Original post by tinkerbella~)
3) Use the fact that the force pulling the rope must equal the frictional force for the box to move at constant velocity. From F=ma, resultant force must be 0 if a=0.

4) Again: F=ma. Find the resultant force, you're given the mass.
What if it doesnt. What if f=ma dnt work. Then what u gna do b

Posted from TSR Mobile
0
5 years ago
#5
(Original post by physicsmaths)
What if it doesnt. What if f=ma dnt work. Then what u gna do b

Posted from TSR Mobile
Cry and give up on both mechanics and life, everything you know is a lie.
1
5 years ago
#6
It's Newtonian mechanics F=ma is always the answer.
0
5 years ago
#7
It's Newtonian mechanics F=ma is always the answer.
Otherwise we use cons of momentum for variable masses. M5 Ch 2

Posted from TSR Mobile
0
5 years ago
#8
(Original post by physicsmaths)
Otherwise we use cons of momentum for variable masses. M5 Ch 2

Posted from TSR Mobile
0
X

new posts
Back
to top
Latest
My Feed

### Oops, nobody has postedin the last few hours.

Why not re-start the conversation?

see more

### See more of what you like onThe Student Room

You can personalise what you see on TSR. Tell us a little about yourself to get started.

### Poll

Join the discussion

#### Poll: What factors affect your mental health most right now? Post-lockdown edition

5.89%
Uncertainty around my education (88)
11.52%
Uncertainty around my future career prospects (80)
10.47%
Lack of purpose or motivation (98)
12.83%
Lack of support system (eg. teachers, counsellors, delays in care) (40)
5.24%
Impact lockdown had on physical health (43)
5.63%
Social worries (incl. loneliness/making friends) (83)
10.86%
Financial worries (51)
6.68%
Concern about myself or my loves ones getting/having been ill (33)
4.32%
Exposure to negative news/social media (48)
6.28%
Difficulty accessing real life entertainment (24)
3.14%
Lack of confidence in making big life decisions (72)
9.42%
Worry about missed opportunities during the pandemic (59)
7.72%