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Understanding Hooke's Law: The Foundation of Elasticity| Chapter 5 Physics 9th

HOOKE'S LAW   Introduction In physics, Hooke's Law is one of the fundamental principles governing how objects deform under external forces . Named after the 17th-century British physicist Robert Hooke, this law provides a crucial understanding of the behavior of elastic materials, such as springs and rubber bands. Whether stretching a rubber band or compressing a spring, Hooke's Law helps explain what happens when forces act on these materials. What is Hooke's Law: Hooke's Law states that the force F needed to extend or compress a spring by some distance x is proportional to that distance. Mathematically, it is expressed as: F= -kx Here k represents the spring constant, which is the measure of the stiffness of the spring, and x is the displacement from the displacement position.  The negative sign indicates that the force exerted by the spring is in the opposite direction of the displacement.  Understanding the Spring Constant: The spring constant k is a critical co

Principle of Moments 9th Physics

  Principle of Moments Considering above figure, lets discuss what is principle of moments. The torque or moment of force produced as spanner is subjected to force as shown above in figure part a. The rotation produced will be in Clockwise direction . The torque or moment of force produced as spanner is subjected to force as shown above in figure part b. The rotation produced will be in  Anticlockwise direction . Statement: "A body is balanced if the sum of clockwise moments acting on the body is equal to the sum of anticlockwise moments acting on the body." Sum of clockwise moments = Sum of anticlockwise moments Example: A meter rod is supported at its middle point O as shown in figure 4.15 (refer book). The block of 10N is suspended at point B, 40cm from O . Find the weight of the block that balances it at point A, 25 cm from O. Data: w1= ? w2=10N Moment of arm of w1=OA=25cm or 0.25m Moment of arm of w2=OB= 40cm or 0.40m Solution: According to the Principle of the moments w