 # Forces Acceleration Newtons Laws Newtons Laws Forces 1

• Slides: 52 Forces, Acceleration, Newton’s Laws Newton’s Laws Forces 1 Forces 2 Forces 3 Forces 4 10 10 10 20 20 20 30 30 30 40 40 40 50 50 50 Question 1 - 10 The amount of matter in an object is called ______  Question 1 - 20 • What is Newton’s 2 nd Law? Answer 1 – 20 Acceleration depends on the object’s mass and on the net force action on the object: • Acceleration =net force /mass • 2 children in a wagon with you pulling – acceleration is faster because the mass is lighter. If you are in the wagon and the children are pulling- the acceleration decreases because mass increases. Question 1 - 30 • For every action, there is an _____ and ________________. • Which Newton’s Law is this? Answer 1 – 30 Equal and opposite REACTION Newton’s Third Law of Motion Question 1 - 40 • What is Answer 1 – 40 Newton’s 3 rd law states that as one object exerts a force on another object, the 2 nd object exerts a force of equal strength in the opposite direction of the 1 st. Question 1 - 50 • What is inertia? Answer 1 – 50 • Inertia is an object’s resistance to change in motion. The greater the MASS, the greater the INERTIA • Ex: An empty aquarium is easier to move than one full of water! Question 2 - 10 • Give an example of a balanced force Answer 2 – 10 • Two people exerting forces on a box. If the force each person exerts is EQUAL, then it is considered a balanced force. Question 2 - 20 • The force of gravity of a person or object at the surface of a planet is known as _______  Question 2 - 30 When a car stops at a stop light and you keep moving forward as the passenger, this is an example of ______. Which of Newton’s Laws is this? Inertia Newton’s 1 st Law of Motion Question 2 - 40 What is unbalanced forces? • Unbalanced forces can cause an object to start moving, stop moving, or change direction. Ex: Two people exert forces on the box in the same direction; the box moves 25 N + 25 N = 50 N Or a drop on a roller coaster ride • The tendency of an object to resist any change of motion is known as _____. Answer 2 – 50 EX: When a car stops suddenly, but you keep moving forward until your seat belt stops you. Question 3 - 10 • Find the net force of two forces: • 15 N 30 N Answer 3 – 10 • 15 N Question 3 - 20 • Find the net force of two forces: • 50 N 50 N Answer 3 – 20 Zero This is a Balanced force Question 3 - 30 • Find the net force of two forces: 35 N 15 N Answer 3 – 30 50 N Question 3 - 40 Solve: • As a roller coaster car starts down a slope, its speed is 4 m/s. But 3 seconds later, at the bottom, its speed is 22 m/s. What is its average acceleration? Answer 3 – 40 • Acceleration= Final Speed – Initial Speed • Time 22 m/s – 4 m/s 3 s 18 m/s 3 = 6 m/s� Question 3 - 50 What is acceleration? Answer 3 – 50 The rate at which velocity changes; increasing speed, decreasing speed; or changing direction Question 4 - 10 What is velocity? What is the equation to find velocity? Answer 4 – 10 • Speed in a given direction. • Velocity = Distance/Time (with direction) Question 4 - 20 • What is the equation for Speed? Answer 4 – 20 Speed = Distance Time Question 4 - 30 • Solve: • A cyclist travels 32 km during the first 2 hours. Then the cyclist travels 13 km during the next hour. Find the average speed of the cyclist. Answer 4 – 30 Average speed of the cyclist is the total distance divided by the total time: • Total distance = 13 km + 32 km = 45 km • Total Time = 2 h + 1 h = 3 h • Average speed = 45 km • 3 h • = 15 km/h Question 4 - 40 What is the Law of Universal Gravitation? Answer 4 – 40 Two objects always exert (apply) gravitational forces on each other. Question 4 - 50 A force that rubs against the surface of another surface is called ________.  Question 5 - 10 • If you know a car travels 30 km in 20 minutes, you can find its ______. Answer 5 – 10 • Speed = Distance/time Question 5 - 20 • You do not know an object’s velocity until you know its ______ and ______. Answer 5 – 20 Speed and direction Question 5 - 30 What is force? Answer 5 – 30 A lift, pull, or push that gives energy to an object, sometimes causing it to start moving, stop moving, or change direction. Question 5 - 40 • Name the 3 types of acceleration. Answer 5 – 40 • Increasing speed • Decreasing speed • Changing direction Question 5 - 50 To increase an objects momentum you need to increase its a. Force and friction b. velocity or mass c. acceleration and friction Answer 5 – 50 b. Mass or velocity