A Level Physics Ocr A Paper 1 Questions And Answers 100% Verified A+ Guaranteed

What does the area under any force-extension graph tell you? {Ans: Work done.}What is the force equation associated with Newton's second law? {Ans: F = ma}How do you find the centre of mass of a 2D object? {Ans: Suspend the object on a pin from a clamp stand. Hang a plumb-line from the pin and draw a line along the vertical line it makes on the object. Repeat this for different points of suspension on the object. The point at which the lines intersect is the centre of mass.}Describe the rubber loading and unloading curves on a force-extension graph. {Ans: Rubber bands do not obey Hooke's Law. The rubber band returns to its original length after the force is removed - elastic deformation - but both the loading and unloading graphs are curved and different. A loop is formed by the loading and unloading curves called a hysteresis loop. The loading curve is steeper as more work is done when stretching the band than when releasing it. Thermal energy is released when the material is loaded and unloaded, represented by the area within the hysteresis loop.}Why do brittle material stress-strain graphs look like they do?