Acceleration
What are the units for acceleration?
m/s2
What is newton's second law?
Force = mass x acceleration
What is the force of gravity acting on a 10kg object?
10kg x 9.8m/s2 =
98N
Define force
Any push or pull (usually on an object)
Draw an example of Newton's third law in action
Equal and opposite reactions
What is the formula to calculate acceleration?
change in velocity over time
For every action there is an ______ and _______ reaction.
Equal and opposite
What is the force of gravity on an object that has a mass of 65 kg?
What is 637 N
When two opposing forces are not equal they are considered ____________ ______________
Unbalanced forces
How much force is exerted when a 5 kg brick hits a wall accelerating at 5m/s2?
15 N
What are the three ways an object can accelerate?
Change speed
Change direction
Change speed and direction
What is Newton's first law of motion?
An object at rest stays at rest, and an object in motion stays in motion, unless acted upon by an outside force.
Calculate the velocity of an object in freefall for 6 seconds.
6s x 9.8m/s2 =
58.8m/s
What is the difference between speed and velocity?
Velocity has direction
Describe two balanced forces acting on an object in this room.
Gravity and the floor on most objects
In a race, a man runs at an initial velocity of 6m/s but gets tired before the end and slows down to 4m/s by the time he finishes the race after 30 seconds.
What is his acceleration?
(4m/s-6m/s)/30sec
.066 m/s2
Which of Newton's Law's is called the Law of Inertia?
A 13 kg object at rest falls off a shelf for 3 seconds. If the objects final velocity was 30 m/s. What force did it hit the ground with?
130 N
Any object that has ________ must also have its own gravity.
Mass
What does this symbol (Δ) represent?
A change
Example: Δv = vf-vi
A car is traveling from NY to NH at 90km/hour consistently. What is the acceleration if they travel for 5 hours.
0 m/s2
Identify how the following action demonstrates all three of Newton's Laws. (Dropping a ball)
1) The ball starts at rest, until dropped meaning gravity has a stronger force on the ball, thus accelerating it.
2) The force the ball hits the floor with is equal to its mass x acceleration.
3) The ball hits the floor and bounces back up with an equal amount of force to it hit with.
A golf ball is thrown straight up into the air at 15m/s, what is it's velocity when it reaches its highest point.
0 m/s
9.8 m/s2 is the value of what?
Acceleration due to gravity
Why don't elephants and feathers fall at the same acceleration on Earth as they would on the moon? Be specific.
The air resistance on Earth can quickly match the force of gravity acting on a feather because of its relatively low mass and high surface area, but it would take much longer for air resistance to match the gravitational pull on an elephane.