Download Activity 77: Mass and Collisions

Activity 77: Mass and Collisions
• Warm up: what is the momentum of
a tennis ball that started at a given
point and was pushed backwards 48
meters in 7 seconds? The tennis ball
weighs .05 kg.
• What is the velocity of a bee flying
at a momentum of 16 kg• m/s if it
weighs 0.001 kg?
Next Quiz!
• Our next quiz will be Wednesday April 13th!
• Activities 76 and 77
• No notecard or notebooks, please study!
• 10 questions, 10 points
Activity 76 Analysis Questions
OneNote Practice Problems
• If a car is going 100 m/s and slows down to 50
m/s in 20 seconds while traveling west, what is
the car's acceleration?
• Calculate the average velocity of a car that travels
556 kilometers northeast in 3.4 hours.
OneNote Practice Problems
• The tortoise and the hare in a road race
to defend the honor of their breed. The
tortoise crawls the entire 1000 m
distance at a speed of 0.2 m/s while the
rabbit runs the first 200 m at 2.0 m/s.
The rabbit then stops to take a nap for
1.3 hours and wakes to finish the last 800
m with an average speed of 3.0 m/s.
Who wins the race and by how much?
OneNote Practice Problems
• A track athlete throws a 2 kg discus into a field
with a velocity of 21 m/s. What is the momentum
of the discus?
• What is the force applied to a wall if the car that
hits it is 2000 kg and was moving at an
acceleration of 70 m/s?
Activity 76 In Case You Missed It
• A force is a push or a pull. The unit for force is
Newton (N).
𝑚
𝑓𝑜𝑟𝑐𝑒 𝑁 = 𝑚𝑎𝑠𝑠 𝑘𝑔 𝑥 𝑎𝑐𝑐𝑒𝑙𝑒𝑟𝑎𝑡𝑖𝑜𝑛 ( 𝑠2)
Activity 76 In Case You Missed It
• Impulse: a force acting over a short interval of time, such
as in a car collision.
• Momentum: a way to quantify the motion of an object.
𝑚𝑜𝑚𝑒𝑛𝑡𝑢𝑚 𝑘𝑔 • 𝑚 𝑠 = 𝑚𝑎𝑠𝑠 𝑘𝑔 𝑥 𝑣𝑒𝑙𝑜𝑐𝑖𝑡𝑦 (𝑚 𝑠)
Activity 76 In Case You Missed It
• Conservation of Momentum: if no additional
forces act on an object or objects, the total
momentum will stay the same.
• Outside forces: air resistance, friction, gravity
Activity 77: Mass and Collision
• Please open your books to page E19.
Activity 77: Mass and Collision
• What is mass? Is it different than weight?
• Mass: how much matter is in an object
• Weight: the amount of gravitational force acting
on an object.
Activity 77: Mass and Collision
• A rocket on Earth weighs 30,000 kg
on Earth because of gravity.
• The same rocket goes to the moon,
what will happen to the mass? What
will happened to the weight?
• That rocket then goes to Jupiter.
What would happen to its perceived
weight? Its mass?
Activity 77: Mass and Collision
• Focus: what does the mass of the cart have to do
with the force it can put on the block?
• Before the activity, does the mass affect the
speed of an object?
• You know from the last activity that the speed can factor
into how much force is put on the block.
Activity 77: Mass and Collision
• With your group, you will design an investigation
to test the relationship between mass and force
exerted by the cart.
• Use the procedure in the book and the Student Sheet.
• Ms. Pyle must see your experimental design before you
begin collecting data!
Activity 77: Mass and Collision
• Using the data you collected, what was the
relationship between the mass of the cart and
the force it exerted on the block?
Activity 77 Analysis Jigsaw
• Each person at your table will get 1-2
analysis questions to work on.
• When Ms. Pyle says, share your answers
with each other, teaching one another why
your answer is what it is.
• As other people at your table are talking,
write their answer in your OneNote
notebook.
Tonight’s Homework
• Study for quiz on Tuesday!
• Activities 76 and 77.