Using the Equations of Motion

Step One: What each term means

• Distance, s, is how FAR you are from your starting position.

Step One: What each term means

START

• Distance, s, is how FAR you are from your starting position.

Step One: What each term means

START

s = 10 m

• Distance, s, is how FAR you are from your starting position.

Step One: What each term means

• Distance, s, is how FAR you are from your starting position.

• No matter HOW you got there…

START

s = -5 m

Step One: What each term means

• Velocity is how FAST you are going

Step One: What each term means

• Velocity is how FAST you are going

v = 10 m/s

Step One: What each term means

• Velocity is how FAST you are going• It can be negative

v = -15 m/s

Step One: What each term means

• Velocity is how FAST you are going• It can be negative• It is simply distance traveled divided by the time.

vave = st

Step One: What each term means

• Acceleration is how quickly the velocity changes.

Step One: What each term means

• Acceleration is how quickly the velocity changes.• Positive a means you are speeding up

Step One: What each term means

• Acceleration is how quickly the velocity changes.• Positive a means you are speeding up• Negative a means you are slowing down

Step One: What each term means

• Acceleration is how quickly the velocity changes.• Positive a means you are speeding up• Negative a means you are slowing down• It is change in velocity divided by the time.

Step One: What each term means

a = Δvt

• Acceleration is how quickly the velocity changes.• Positive a means you are speeding up• Negative a means you are slowing down• It is change in velocity divided by the time.

Step One: What each term means

• Acceleration is how quickly the velocity changes.• Positive a means you are speeding up• Negative a means you are slowing down• It is change in velocity divided by the time.

a = =Δvt

v - ut

Step One: What each term means

• Acceleration means the final velocity is NOT the same as the initial velocity.

Step One: What each term means

• Acceleration means the final velocity is NOT the same as the initial velocity.

• We use initial velocity = u

Step One: What each term means

• Acceleration means the final velocity is NOT the same as the initial velocity.

• We use initial velocity = u• We use final velocity = v

Step One: What each term means

• Acceleration means the final velocity is NOT the same as the initial velocity.

• We use initial velocity = u• We use final velocity = v• If v > u then we are speeding up (a is positive)

Step One: What each term means

• Acceleration means the final velocity is NOT the same as the initial velocity.

• We use initial velocity = u• We use final velocity = v• If v > u then we are speeding up (a is positive)• If v < u then we are slowing down (a is negative)

Equation One: v = u + at

• A train accelerates from rest at 3 m/s2. How fast is it going after 30 seconds?

• My Nissan Frontier goes from 0 to 60mph in 9.2 seconds, What is the acceleration?

• A car traveling at 30 m/s decelerates at 7 m/s2. How long is it before it comes to rest?

• An ice puck slows due to friction at 1.7 m/s2. I hit the puck at one end of the rink, and when it hits the goal, 12 seconds later, it is going at 19 m/s. At what speed did I hit the puck initially?

Equation Two: s = ut + ½at2

• A train accelerates from rest at 3 m/s2. How far has it gone after 30 seconds?

• From a rolling start at 20 mph, Jewel Alderson can cover the 400 meter Trader Joes parking lot in 11 s, What is the acceleration of her Hyundai?

• An ice puck on asphalt slows due to friction at 6.7 m/s2. It travels 100 meters in 7 seconds. At what speed did I hit the puck initially?

Equation Three: v2 = u2 + 2as

• A train accelerates from rest at 3 m/s2. How fast is it going when it hits the car on the track, 500 meters down the line from the station?

• Traveling at 60 mph I see an old person walk into the road 300 meters ahead. Feeling in a good mood, I decide to break, and the car slows at a rate of 6.5 m/s2. What is the fate of the pensioner?

• After joining the freeway I can accelerate from 40 mph to 90 mph in 11 seconds. How far do I travel along the freeway before I get to 90?

Motion Under Gravity• I drop an egg from the bridge in Balboa Park and

it hits a car windscreen 5 seconds later. How high is the bridge?

• I throw a pool ball straight up into the air and it hits the ground 3.5 seconds later. How fast did I throw the ball?

• I launch a tennis ball at 45o at a velocity of 40 m/s. How far away does it hit the ground?

• A golfer hits a ball and 3 seconds later gets a hole in one If the hole was 250 meters away, what was the highest point in the ball’s trajectory?