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A body of mass 40kg stands on aweighing machine in an accelerated lift the reading on the scale of the weighing machine is 300. Find the magnitude and direction?
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A body of mass 40kg stands on aweighing machine in an accelerated lift...
M=40kg
F=300N
suppose that g=9.8m/s^2

Now, when the lift goes down, 2 types of accelerations are applied, 
1. gravitational acceleration
2.acceleration of life

By thinking about the FBD of the lift,
if the lift moves down, the sum of acceleration = g-a
and if it moves up, it is g+a

[why? Becuase when the life moves, an illusory acceleration is applied on it, which is 'a' here]

That means,
1. if the lift is moving upwards,
F=m(g+a)
300=40(10+a)
a= -2/5 m/s^2

2. if lift is going down,
F=m(g-a)
300=40(10-a)
a= +2/5 m/s^2

Now the directions:
 1.if the lift moves downwards, the magnitude of acceleration is +2/5 m/s^2
2.if the lift moves downwards, the magnitude of acceleration is -2/5 m/s^2
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A body of mass 40kg stands on aweighing machine in an accelerated lift...
Problem Statement:
A body of mass 40kg stands on a weighing machine in an accelerated lift. The reading on the scale of the weighing machine is 300. Find the magnitude and direction.

Solution:

Step 1: Analyzing the Situation
- In this scenario, the body is standing on a weighing machine in an accelerated lift.
- The weighing machine measures the normal force exerted by the body on the machine.
- The reading on the scale of the weighing machine is 300, which is the normal force experienced by the body.

Step 2: Understanding the Forces Acting on the Body
- In this case, there are two main forces acting on the body:
1. Gravitational force (mg): This force is always directed downwards and has a magnitude equal to the product of mass (m) and acceleration due to gravity (g).
2. Normal force (N): This force is exerted by the weighing machine and is equal in magnitude but opposite in direction to the gravitational force.

Step 3: Applying Newton's Second Law
- According to Newton's second law of motion, the net force acting on an object is equal to the product of its mass and acceleration.
- In this case, the net force is the difference between the gravitational force and the normal force.
- Therefore, the net force is given by the equation: Net force = mg - N.

Step 4: Solving the Equation
- We know that the mass of the body is 40kg and the acceleration due to gravity is approximately 9.8 m/s^2.
- The normal force is given as 300 (reading on the scale of the weighing machine).
- Substituting these values into the equation, we get: Net force = (40 * 9.8) - 300.

Step 5: Calculating the Net Force
- Evaluating the equation, we find: Net force = 392 - 300 = 92 Newtons.

Step 6: Interpreting the Result
- The net force acting on the body is 92 Newtons.
- The direction of the net force depends on the relative magnitudes of the gravitational force and the normal force.
- Since the normal force is smaller than the gravitational force, the net force is directed downwards.

Conclusion:
- The magnitude of the net force acting on the body is 92 Newtons, and its direction is downwards.
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A body of mass 40kg stands on aweighing machine in an accelerated lift the reading on the scale of the weighing machine is 300. Find the magnitude and direction?
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