A mass of 30kg on a smooth horizontal table is tied to a cord running

In summary, the 30 kg mass on a smooth horizontal table is tied to a cord running over a frictionless pulley to a 10 kg mass. The resulting tension in the cord is 147N. The forces acting on the masses are gravity and tension, with the 30 kg mass also experiencing a normal force from the table. Both masses have the same acceleration of 4.9 m/s^2.
  • #1
cmkc109
103
0

Homework Statement




A mass of 30kg on a smooth horizontal table is tied to a cord running along the table over a frictionless pulley mounted at the edge of the table. A 10kg mass is attached to the other end of the cord. When the two masses are allowed to move freely the tension in the cord is


can someone please check if the answer is 147 N?
Because the solution given is 75N but I don't think I did anything wrong.
Thanks
 
Physics news on Phys.org
  • #2
You answer is incorrect. Show your working.
 
  • #3
(30)9.8) - T = (30) a
+ [ T - (10 (9.8) = 10a ]

196 = 40a
a= 4.9 m/s^2

T - 98 = 10(4.9)
T= 147N
 
  • #4
What forces act on the 30 kg mass? What forces on the 10 kg mass? What are the resultant accelerations?
 
  • #5
voko said:
What forces act on the 30 kg mass? What forces on the 10 kg mass? What are the resultant accelerations?


gravity force and tension force
and acceleration i got is 4.9 , they have the same accleration because it is the same rope
 
  • #6
Gravity and tension act on the little mass. The big mass is on the table, so there is also the reaction force, which cancels the force of gravity on it.
 
  • #7
voko said:
Gravity and tension act on the little mass. The big mass is on the table, so there is also the reaction force, which cancels the force of gravity on it.


oh, so that will be the normal force?
 
  • #8
Of course.
 
  • #9
voko said:
Of course.

ok, thanks for ur help!
 

Related to A mass of 30kg on a smooth horizontal table is tied to a cord running

1. How does the mass affect the motion of the cord?

The mass of the object affects the tension in the cord and therefore the acceleration of the object. A heavier mass will require more force to accelerate it, resulting in a higher tension in the cord.

2. What is the relationship between the tension in the cord and the mass?

The tension in the cord is directly proportional to the mass of the object. As the mass increases, so does the tension in the cord.

3. How does the smoothness of the table affect the motion of the mass?

A smooth table reduces the amount of friction between the mass and the surface, allowing for smoother and more consistent motion. This means that the object will experience less resistance and will be able to move more easily.

4. Is the motion of the mass affected by the length of the cord?

Yes, the length of the cord affects the motion of the mass. A longer cord will allow for a greater range of motion, while a shorter cord will limit the distance the mass can travel.

5. What happens to the motion of the mass if the table is not horizontal?

If the table is not horizontal, the motion of the mass will be affected by the force of gravity. The mass may roll or slide down the incline, depending on the angle of the table. The tension in the cord may also change as the mass moves along the incline.

Similar threads

  • Introductory Physics Homework Help
Replies
10
Views
2K
  • Introductory Physics Homework Help
Replies
4
Views
1K
  • Introductory Physics Homework Help
Replies
21
Views
3K
  • Introductory Physics Homework Help
Replies
30
Views
2K
  • Introductory Physics Homework Help
Replies
4
Views
2K
  • Introductory Physics Homework Help
Replies
6
Views
1K
  • Introductory Physics Homework Help
Replies
9
Views
5K
  • Introductory Physics Homework Help
Replies
15
Views
2K
  • Introductory Physics Homework Help
Replies
8
Views
2K
  • Introductory Physics Homework Help
Replies
2
Views
5K
Back
Top