Tonight… Revise the last three explanations What effect does speed have on kinetic energy? Does the ball accelerate after it leaves the ramp? Do mass and force affect acceleration? Write them all on one piece of paper You may type or write it (typed is preferred) You will turn them all in tomorrow, one will be picked for grading.

Standard I can determine what causes objects to speed up, slow down  or change direction Entry Task Update table of contents Pg. 41 – Applying Newton’s Second Law Meet on Pg. 40 You will need a calculator! Learning Target How do we apply Newton’s Second Law At home Submit Explanations for a grade

Do Mass and Force affect Acceleration? Share explanations Mass and force do affect acceleration. I know this because when the mass was greater the car accelerated slower. When the force was greater the car accelerated faster. Since Newton’s second law states that mass and force affect acceleration, and mass and force changed acceleration of our car, then I know that mass and force do affect acceleration.

Tonight… Revise the last three explanations Revise and submit all of them on-line by Tuesday 11:59:59 PM One will be picked for a grade.

Calculate the acceleration of each car from Thursday’s lab Convert the mass of the car to kg (divide each mass by 1000) 57g ÷ 1000 = .057kg Acceleration = Force divide Mass A = .3 N ÷.057 kg = 5.2 m/s2 Write the acceleration next to the net force on each system 5.2 m/s2

.3 The car speeds up really fast when released 57g 5.2 m/s2 1.8 m/s2 1.2 m/s2 51.6 m/s2

Does gravity pull on all objects the same?

How is this possible? .5 g 1000 g Fall at same rate

What we know… More mass = more gravity Acceleration is a change in motion Objects change their motion when an unbalanced force acts on them More mass = more friction More mass = more inertia ______ ______ ______________ ______ No friction on the moon ______

Explanation Do mass and force affect acceleration? 40 41

Move Your Data from Pg. 39: Mass vs. Weight

Convert g to kg. (g ÷ 1000) Use Acceleration = Force ÷ Mass What is the relationship between mass acceleration? Use Acceleration = Force ÷ Mass

Gravity Accelerates Equally ~9.8 m/sec2 Gravity accelerates (changes the motion) of all things at the same rate

Explanation Do mass and force affect acceleration? 40 41

High gravitational force Low gravitational force Large Mass High gravitational force High inertia Low Mass Low gravitational force Low inertia Same acceleration

Force = 1,623 x 6.4 = 10, 391 N Force of an Corvette engine Acceleration 6.4 m/sec2 Mass of car: 1,623 kg Force = 1,623 x 6.4 = 10, 391 N Reveal the first three bullets and ask students to use the formula to find the acceleration of the car. Really hold their hand on the first one. When everyone has an acceleration. Have a few groups share. They should all be close to 4.2. Reveal the correct and answer and then reveal the mass of the car. Remind them to use F = M x A to find the force the engine uses to accelerate the car.

16,800,000 N Force of a Titan Rocket A = 18.66 m/s2 Mass : 900,000 Kg F = 18.66 m/s2 x 900,000 Kg 16,800,000 N Repeat the process from the last slide for this one, but give them a little more leash

Solar Sails Uses the Solar Wind (charged particles from the sun) to create a constant fore and accelerate a space craft through space.

Space Craft mass: 100 Kg (about 220 lbs) F = 100 kg x .005 = .05 N Force on a Solar Sail: By the time it reaches pluto it is going 45,000 m.sec Acceleration = .0005 m/s2 Space Craft mass: 100 Kg (about 220 lbs) F = 100 kg x .005 = .05 N Repeat the other force calculation instructions. Marvel at the difference a little constant force can have over a long period of time – with no other force to balance it. This eventually go 4 times faster than the rocket with .000000313% of the force

Tonight… Revise the last three explanations Revise and submit all of them on-line by Tuesday 11:59:59 PM One will be picked for a grade.