Newton’s 1st and 2nd Laws of Motion

1. To find out how strong or weak a force is, it is measured in units called __________. 2. Friction is a contact/non-contact force. 3. True or False: Electric forces exist between two magnets. 4. Julie is 50 kg. Is this her mass or her weight? 5. Does gravity push or pull objects with mass?

Anthony’s weight/mass is 70kg. Chantelle jumps off a diving board. Which force is making her fall? Lightning strikes a car. Which force created lightning? Hank is pulling on his sister’s stretchy hair tie. What is the name of the force in the hair tie? Tension is a contact/non-contact force. True/False: Gravity is both a pushing and a pulling force. What is the weight of a truck that has 2000kg? (g = 10 m/s2)

A book slides to a stop on the surface of a desk A book slides to a stop on the surface of a desk. Which type of friction force is this an example of? When a skydiver falls, air pushes up on him. Which type of friction force is this an example of? When two masses are brought closer together, the gravitational force between them decreases/increases. The gravitational force of Earth, a big planet, causes objects to accelerate towards it. This gravitational force acting on another mass is also called the mass’s __________. Ramesh, who is 60kg, buys a 5kg watermelon even though it’s winter because he’s a fancy guy. What is the weight of the watermelon?

True/False: Jacob has more mass on Earth than in outer space. Julie pulls Andrew with a force of 100N. Melissa pulls him in the opposite direction with a force of 100N. The forces on Andrew are balanced/unbalanced. Shrek pushes a big rock that is covering the entrance to a cave. The rock only starts to move when he applies a force of 200N. What type of friction force was going against Shrek? Magneto is a supervillain from X-men. Judging from him name, he can attract metal objects with which type of force? Air resistance makes a feather fall slowly. What type of force is air resistance?

A 55kg student is walking their dog. How much does the student weigh A 55kg student is walking their dog. How much does the student weigh? (g = 9.8 N/kg) If a UFO transports the student to Mars, the student now weighs 187N, what is the acceleration due to gravity on Mars? True/False: Mass is just another word for the Force of Gravity. True/False: An object requires a constant force in order to keep moving at a constant velocity. True/False: All objects have inertia

True or False: A 5 kg bag has more inertia than a 5mg feather. True or False: Friction makes an object moving to the right accelerate to the right. Newton’s First Law states that, in the presence of balanced forces only, an object moving to the left will: a) eventually slow down and stop b) continue moving to the left c) speed up towards the left The larger the masses, the __________ the gravitational force between them.

Which has more inertia, a 10kg sack of rice or a 30 kg young child? Unbalanced forces cause a(an) _____________. What force is this an example of? A heavy bag slides to a stop on top of ice. A 40N net force pulls a 4kg rock. What is the acceleration of the rock? What is the net force on a falling 60kg skydiver who has an acceleration of 0 m/s2?

1. 2. 3. 4. A person sitting on a chair 9. Δv = 0? 5. 20 N left and 30 N right 10. a ≠ 0 6. An object at constant speed 11. a = 0 7. An accelerating plane 12. Δv ≠ 0 8. An object at rest 13. A stopping car

Homework Prepare to present an example of Newton’s First Law of Motion. You must accompany your presentation with a careful explanation of why it is Newton’s First Law. (See the example in your book.) You must be a part of the performance and/or explanation.

Newton’s Second Law An unbalanced force (____ force) will cause an acceleration in the same direction. F = m a Greater force causes greater acceleration. Example: Nicole pushes a 1000 kg car with 50 N of force. What is the acceleration of the car?

Newton’s 2nd Law Lab Aim: To investigate how mass affects acceleration. Hypothesis: Procedure: [Use the SAME force!] 1. Make a cart large and strong enough to hold 4 eggs. 2. Weigh the cart and record. 3. Push cart, record distance. 4. Place one egg in the cart, and weigh. Repeat step 3. 5. Repeat step 4 until you have recorded the distance for the cart holding four eggs. Results: (Create your own table)

Distance travelled (m) Number of eggs in cart Mass (grams) Mass (kilograms) Distance travelled (m) 2 0.002 0.42 1 63.18 0.06318 0.44 121.34 0.12134 0.35 3 181.68 0.18168 0.33 4 245.00 0.245 0.26

Conclusion: The carts with more _______ travelled a __________ distance when pushed with the ______ force.

Discussion questions: (Answer in complete sentences) How does increasing the mass affect the distance travelled by the cart? Predict how far the cart will roll if you added another egg. Explain the results of your experiment using Newton’s 2nd Law of Motion. What happens to the acceleration of an object if more force is applied? Extra question: How much force is required to move a 250 kg cart with an acceleration of 4 m/s/s?

Discussion: Increasing the mass _________ the distance the cart travelled. The cart would roll _____m if another egg was added. Newton’s Second Law of Motion states that an unbalanced force causes an object to accelerate. So according to the law, a = F/m, keeping the force the _______but increasing the mass would __________the acceleration of the cart, so the cart experiences a _________speed change, and so it travels a _________distance. If more force is applied, the acceleration of an object will ___________. It takes 1000N of force to accelerate a ____kg cart by 4 m/s/s.

Net Force (N) Mass (kg) Acceleration (m/s/s) 10 2 20 4 5