Year 12 Physics Exam Questions with Correct Answers

Newton's Law of Universal Gravitation states - ANSWER-Any two bodies in the universe attract each other with a force that is directly proportional to the product of their masses and inversely proportional to the square of the distance between them. Newton's Law of Universal Gravitation Equation components - ANSWER-F = Force G = Gravitional constant m = mass of object r = distance between the centre of the two obejcts G = - ANSWER-6.67×10−11 N m2 kg−2 Size of forces - ANSWER-Forces between everyday objects have magnitudes of around a millinewton (mN) or less. Forces of this size are hard to detect without specialised equipment and can usually be considered negligible. Effect of gravity and Newton's third law - ANSWER-According to Newton's third law of motion, forces occur in action-reaction pairs. This means that if the Earth exerts a gravitational force on the Moon, then, conversely, the Moon exerts an equal and opposite force on the Earth. Effect of gravity and Newton's second law - ANSWER-using Newton's second law of motion, we can see that the effect of the gravitational force of the Moon on the Earth will be much smaller than the corresponding effect on the Moon. Gravity in the solar system - ANSWER-Although the accelerations caused by gravitational forces in the worked examples above are small, over billions of years they created the motion of the solar system. The Earth-Moon system - ANSWER-the acceleration of the Moon is many times greater than that of the Earth, which is why the Moon orbits the Earth. Weight formula - ANSWER-F = m × g F = force m = mass g = force due to gravity Gravitational fields - ANSWER-A region in which a gravitational force is exerted on all matter within that region. Gravitational fields around large objects - ANSWER-The gravitational field around a large object like a planet is much more significant than around a small object. The