21- Jimmy is skating at 25 m/s. He experiences an acceleration of -5 m/s². How many seconds will it take him to stop?
t=5 seconds
100
12- A cart rolling down an incline for 5 seconds has an acceleration of 4 m/s². If the cart has a beginning speed of 2 m/s, what is its final speed?
Vf= 22 m/s
100
11- A car traveling at a speed of 30 m/s encounters an emergency and comes to a complete stop. How much time will it take for the car to stop if its rate of deceleration is 4 m/s²?
t=7.5 seconds
100
What is motion?
When the distance between to objects changes
100
A child walking towards his mother
straight line
200
20- A ball is dropped from the top of a 73m tall building. How fast will the velocity be when it hits the ground?
+37.82 m/s or -37.82 m/s
200
13- A car accelerates at 3 m/s² from rest for 10 seconds. How far does it travel?
150m
200
5- An object starts from rest and accelerates uniformly to a speed of 7m/s in 2s. Determine the object´s displacement
(delta x= +7m)
200
Which of the following is an example of speed?
a) 23m/s b) 23 m/s North
23 m/s
200
A ferris wheel
Circular motion
300
18- A car accelerates from rest at a constant rate of 2 m/s² for 5 seconds. A) What is the speed of the car at the end of that time?. B) How far does the car travel in this time?
Vf= 10m/s. Delta x= 25m
300
14- A car is moving at 100 Km/hr. It stops in 5 seconds. What is the car´s acceleration?
-5.56 m/s²
300
4- An object is moving with a velocity of +24m/s when it begins slowing down. The magnitude of its acceleration is 9m/s². What is the object´s velocity when its displacement is +25m from the point where it began slowing down?
(Vfx= +11.22m/s or -11.22m/s)
300
What does the velocity of an object tell you? (what is velocity?)
The direction in which an object is moving
300
Very loud speakers
Vibration
400
19- A stone drops vertically from a tall building. It hits the ground at a speed of 29 m/s and creates a hole 94cm deep. A) Find its deceleration after hitting the ground. B) How long does it take the stone to stop?
a= -447 m/s². t= 0.064 seconds
400
15- A ball is thrown off a building. If the ball is thrown up at 5 m/s and lands 3 seconds later, a) Find the height of the building. B) Find the impact velocity of the ball
Delta x= -29.1m/ Vf= -24.4 m/s
400
6- An object has an initial velocity of +7m/s. It has a constant acceleration which is causing it to slow down. The object reverses direction after moving +15m. Find its acceleration.
(ax= -1.66 m/s²)
400
What does acceleration tell you? (What is acceleration?)
It tells you if an object is speeding up or slowing down
400
Batting a baseball
Projectile
500
17- Mark is running at a constant speed of 3 m/s. When he is 30 m in front of Adam, Adam begins to chase after Mark. If Adam accelerates at a constant rate of 0.2 m/s², from rest, how far will he have to run before he catches up to Mark?
143.64m
500
16- A car is sitting at a red light. The instant the light changes to green, a truck passes the car. The truck is moving at a constant speed of 10 m/s. The car begins to accelerate at 2 m/s² (at the very instant the light turns green). How far does the car have to travel before it catches up to the truck?
100m
500
10- Bob moves for 5s at a constant velocity of 3m/s. Starting from rest, what constant acceleration must Alice maintain to run the same distance as Bob in the same time?
(aAlice= +1.2 m/sec²)
500
Objects fall due to gravity. What is the acceleration of any object as it falls?