2. As stated on physiscsclassroom. com Newton's second law of montion pertains to the behaviour of objects for which all existing forces are not balanced. It states that the acceleration of an object is dependent upon two variables :. the net force acting upon the object;. the mass of the object;

3. The acceleration of an object depends directly upon the net force acting upon the object, and inversely upon the mass of the object. As the net force acting upon an object is increased, the acceleration of the object is increased, and as the mass of an object is increased, the acceleration of the object is decreased.

4. It can be expressed with a mathematical equation: F= M x A FORCE= MASS X ACCELERATION

5. Aristotle was the first to look at Newton's laws. Aristotle's view were widely accepted because they seemed to follow what everyone observed through nature.

6. Over a period of 20 years, Galileo observed the motions of objects rolling down various inclines and attempted to time these events. He discovered that the distance an object traveled was proportional to the square of the time that it was in motion.

7. Newton wanted to know why acceleration occurred. Newton had to give to science and physics the concept of a force which was mostly unknown at that time. He clearly demonstrated that: acceleration is caused by an unbalanced force acting on an object. gravity is just a special type of acceleration.

8. Newton's second law applied to the game of bowling: Having different masses of bowling balls will create different accelerations for each ball going down the lane. The more acceleration the ball has, the harder the ball will hit the pins. It all varies on how much force is exerted and how much mass to acceleration the bowling ball has.

9. Answers 1. The cause of acceleration is Force, Acceleration is produced through the equation: acceleration = Change in Velocity/Time interval 2. The combination of all the forces that act on an object is called Net Force. 3. If forces of 10N and 20N act on an object, both moving in the same direction the Net force is 30N

10. 4. If a force of 50N is exertedon an object in one direction, and a force of 30N is exerted in the opposite direction, Then the resulting net force is 20N 5. If a cart is being moved by a net force, and then the net force is doubled, the acceleration of the cart will also be doubled. 6. If a cart is being moved by a net force, and then a load is dumped into it and the weight is doubled, The acceleration changes to be half of what it was. because the same force cannot push double the weight at the same acceleration.

11. 7. Directly proportional means that as one would inscreease, the other would increase at the exact same rate, and as one would decrease, the other would decrease at the exact same rate. such as acceleration to net force - as the net force is increased, the acceleration will increase. Inversely proportional refers to two values that would increase or decrease separately, as one value would increase, the other would decrease, and as one would decrease, the other would increase. Such as mass and acceleration - with a constant net force, if you increase the mass, the acceleration will decrease, and if you decrease the mass, the acceleration will increase. 8. Newton's law states: The acceleration produced by a net force on a body is directly proportional to the magnitude of the net force, in the same direction as the net force, and inversely proportional to the mass of the body. - Acceleration = Net force/ Mass 9. How much force must a 20000-kg rocket develop to accelerate 1m/s2?F=MA F=20000KG X 1M/S2 = 20000N

12. 10. How much support force does a table exert on a book that weights 12N when the book is placed on the table = 0N 11. there are 100N of tension exerted in the strand. in each strand there are 25N of tension. 12. Friction is a force that always acts in a direction to oppose motion. It is due to irregularities in the two surfaces that are in contact. 13. Net force= 0N Acceleration= 0N The pressure is the force per unit. Force is what produces accelaration. P=F/A

13. 16. The 2-kg rock will fall with the same acceleration as the 1-kg rock, because they are both free falling and have the same air resistance. Newton's second law proves that you need to consider the mass. For example, 10 times as much force acting on 10 times the as much mass will produce the same acceleration as 1/10 the force acting on 1/10 the mass. This can be seen in the equation, F/M =f/m 17. A coin and a feather in a vacuum tube can fall with the same acceleration because there is no air resistance. Mass doesn't affect an object that is falling in a vacuum.

14. 18. A coin & a feather fall with different accelerations in the presence of air. Air resistance decreases the net forces of each object(not much for the coin, but a lot for the feather). Air resistance builds up to counteract the feather's weight. When the air resistance of the feather equals the weight of the feather, the net force is zero and no further acceleration occurs, the feather's terminal speed. Air resistance on the coin has less effect and is very small compared to the weight of the coin. So, the coin would have to fall for several seconds for air resistance to increase. Terminal speed takes longer to be reached with the coin so it's acceleration continues. 19. The air resistance that acts on a 100 N bag of nails starts with an acceleration of zero. This makes the net force 0N because the gravity force is 100N down. Air force must be 100 N up to balance it out and create a net force of 0N. 20. When terminal speed is reached, the air resistance and the weight of the falling object balances out.

15. 21. All things being equal, a heavier skydiver has a greater terminal speed than a lighter skydiver because air resistance is less effective on the heavier skydiver. This means that the heavier person had a longer time to accelerate, where the lighter person's air resistance caused them to reach terminal speed sooner, terminating their acceleration. For both terminal speeds to be equal, you could add weights to the lighter skydiver to equal the weight of the heavier person. 22. The net force acting on a 25-N freely falling object is the weight, 25N. When it encounters 15N air resistance the net force is 10N. 25N are going down, 15N is the resistance, 10N is pushing up. When it falls fast enough to encounter 25N air resistance, the net force is 0N. It will not have any acceleration and it is at terminal speed.