Applying Newtons laws n an inclined surface with two masses

In summary, the conversation discusses applying Newton's laws to a system of two blocks connected by a cord on inclined and frictionless surfaces. The direction of motion and acceleration of the blocks are determined by the force and weight of each block, and the Pythagorean theorem can be used to find the total acceleration. It is also noted that in this case, frictional forces can be disregarded.
  • #1
e_burke
5
0
applying Newtons laws on an inclined surface with two masses

Homework Statement


Two blocks connected by a cord passing over a small, frictionless pulley rest on frictionless planes (diagram attached)
a) which way will the system move when the blocks are released from rest?
b) what is the acceleration of the blocks?
what is the tension in the cord


Homework Equations


Newtons laws


The Attempt at a Solution


i have not gotten very far in this question as i keep going around in circles, actually i am finding this whole topic difficult but this is my attempt

a) find the force each block the largest force determines which way it will slide

w1 =mg
=100 x 9.8
=980
w2 =50 x 9.8
= 490
in component form
x1 = wsin30 y1 = wcos30
y2 = wsin53 y2 = wcos53

f=ma
but this is where i get stuck
im not sure if i need to take into the block attached at the other end or take each side of the triangle in isolation

i hope you understand cause I am not sure if i am making any sense
thanks in advanced
erin
 

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  • #2
Which is greater?
100 g sin 30 or
50 g sin 53.
Direction of motion depends on that. You don't have to account frictional forces in this case, since its given that the planes are frictionless.
 
  • #3
thanks for that so the system moves to the right
to do part b)
is the x component of acceleration equal to (980sin30+490sin53)/150
which equals 5.88
then you do a similar thing for the y component using the cos values
then to work out the total acceleration you use Pythagorean therm
resulting in 9.625
is this the correct method of working
 
  • #4
e_burke said:
thanks for that so the system moves to the right
to do part b)
is the x component of acceleration equal to (980sin30+490sin53)/150
which equals 5.88
then you do a similar thing for the y component using the cos values
then to work out the total acceleration you use Pythagorean therm
resulting in 9.625
is this the correct method of working

Why use the Pythagorean theorem to find out the total acceleration? :confused:
There is no frictional force acting on either of the two blocks. Which component of weight causes the body to accelerate?
 

1. What are Newton's laws of motion?

Newton's laws of motion are three fundamental principles that describe the behavior of objects in motion. The first law states that an object will remain at rest or in uniform motion in a straight line unless acted upon by an external force. The second law relates the force applied to an object to its mass and acceleration. The third law states that for every action, there is an equal and opposite reaction.

2. How do Newton's laws apply to objects on an inclined surface?

On an inclined surface, the force of gravity can be broken down into two components: the force perpendicular to the surface (normal force) and the force parallel to the surface (weight). According to Newton's first law, an object will remain at rest or in motion with a constant velocity if the net force acting on it is zero. On an inclined surface, the normal force and weight can be balanced to create a net force of zero, resulting in the object remaining at rest or moving at a constant velocity.

3. What is the relationship between mass, force, and acceleration in Newton's second law?

Newton's second law states that the force applied to an object is equal to the mass of the object multiplied by its acceleration. This can be expressed as the equation F=ma, where F is force, m is mass, and a is acceleration. This means that the greater the mass of an object, the more force is required to accelerate it, and the greater the force applied to an object, the greater its acceleration will be.

4. How does friction affect the application of Newton's laws on an inclined surface?

When an object is on an inclined surface, it may experience friction, which is a force that opposes motion. Friction can affect the acceleration of the object, as it acts in the opposite direction of the object's motion. This means that the net force on the object will be less than the force applied, resulting in a slower acceleration. To account for friction, the coefficient of friction can be included in the calculation of the net force.

5. How do Newton's laws explain the motion of two masses on an inclined surface?

When two masses are on an inclined surface, each mass will experience its own weight and normal force. According to Newton's second law, the net force acting on each mass will determine its acceleration. If the masses are connected by a pulley system, the force exerted on one mass will be transferred to the other mass through the tension in the rope. The acceleration of each mass will depend on their individual net forces and masses, but they will move in opposite directions due to the tension in the rope.

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