Two steel blocks are at rest on a frictionless horizontal surface. Block X has a mas of 3.0 kg ans is attacthed by means of a light taut string to block Y that has a mass of 12 kg. A force of 45 N (E) is applied to block x. Calculate the force block Y exerts on block x.
I don't have any idea of how to go about do this question. I think it's related to newton's 3rd law about action-reaction forces but I don't know any else. Could someone please guide me in the right direction? Thanks
The 45N force accelerates both masses at a rate
a = 45/(3 + 12) = 3 m/s^2
The taut string between X and Y applies an accelerating force to block Y that equals f = m a = 12 kg * 3 m/s^2 = 36 N. The reaction force upon block X is 36 N in the opposite direction (West).
You are correct that Newton's third law is involved
Yes, you are correct that Newton's third law of motion applies here. According to Newton's third law, for every action, there is an equal and opposite reaction.
In this case, when you apply a force of 45 N (E) to block X, block Y exerts an equal and opposite force on block X. This is because the string connecting the two blocks transmits the force.
To find the force block Y exerts on block X, you can use Newton's third law. The force applied to block X is 45 N (E). Therefore, the force block Y exerts on block X is also 45 N, but in the opposite direction (W).
So, the force block Y exerts on block X is 45 N (W).
To solve this problem, you can consider Newton's laws of motion and apply the concept of action-reaction forces.
As per Newton's third law, for every action, there is an equal and opposite reaction. In this case, when you apply a force to block X, there will be an equal and opposite force acting on block Y.
Let's break down the problem into smaller steps:
1. Find the acceleration of the system:
Since the blocks are connected by a string, they will have the same acceleration. Apply Newton's second law to block X:
F_net = m_X * a
a = F_net / m_X = 45 N / 3.0 kg = 15 m/s^2
2. Calculate the tension in the string:
The force acting on block Y is the tension in the string, which is equal to the force applied to block X. Therefore, the tension is also 45 N.
3. Calculate the force exerted by block Y on block X:
Since the blocks have the same acceleration, the force exerted by block Y on block X can be calculated using Newton's second law applied to block Y:
F_net_Y = m_Y * a = 12 kg * 15 m/s^2 = 180 N
Therefore, block Y exerts a force of 180 N on block X.
Remember that the tension in the string is the same in both blocks as they are connected. The force applied to block X creates the same tension, which in turn creates a reaction force by block Y.