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Evidence 1

Jorge Nicolas Moctezuma Arellano

12/02/2021

Matter and energy

Free-fall Equations: v f =v 0 +¿

1 2 y= v0 t + g t 2 Initial values: V0 = 0 y0 = 0 a = g = -9.8 m/s2

Graphs and explanation:

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Position starts at zero. It changes from zero to negative because the object is always below the starting point. The rate of change in position increases with time.

Velocity starts at zero because the object is dropped. Velocity is always negative because its moving downwards Velocity increases constantly because acceleration is constant

Acceleration is constant Acceleration is always -9.8 m/s Acceleration is negative because the object is forced down

Problem solving: A ball that was resting is dropped and falls during 5 seconds. What are its position and velocity on that instant?

Vertical Throw Upwards Equations: 1 2 y = v f t− g t 2 1 2 y= v0 t + g t 2 Initial values: t=5s Y0 = 0 Yf = 0 a = g = -9.8 m/s2

Graphs and explanation:

 

The object moves upwards as it is thrown, but as time progresses the force of gravity brings it down again. Position start on 0. The object falls when it impacts the ruff.

20 0 -20

y (m)



0

1

2

3

4

5

6

-40 -60 -80 -100

time (s)



V (m/s)

Velocity 10 0 0 -10 -20 -30 -40 -50

 1

2

3

4

5

6



The speed starts at 18 because it is the force applied to launch it. Velocity becomes negative as it proceeds downward. The speed is always constant, so it increases.

time (s)

 

The acceleration will always be -9.8 because it is the gravity of the earth. Acceleration is always constant. Since gravity pulls things down to earth, it is negative.

Acceleration

Acceleration 

-8.8 -9 0 -9.2 -9.4 -9.6 -9.8 -10

1

2

3

time (s)

1.

Problem that is resolving: A hammer is thrown vertically up towards a roof that is 16m up. What is the minimum initial velocity required to arrive there?

4

5

6

Vertical Throw downwards Equations: Initial values: d=0 Vf = 0 a = g = -9.8 m/s2 20 0

0

1

2

3

4

5

6

y (m)

-20

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The initial point is 0. It goes down because the brick is falling.

-40 -60 -80 -100

time (s)

V (m/s)

Velocity 10 0 -100 -20 -30 -40 -50

1

2

3

4

5

6

  

The brick wins velocity by falling. The velocity starts on 0 because its dropped. Velocity is constant because it keeps falling.

time (s)

Acceleration

Acceleration -8.8 0 -9 -9.2 -9.4 -9.6 -9.8 -10

1

2

3

time (s)

4

5

6

 

Acceleration is always constant. The acceleration is because of gravity pulling down the brick.

Problem: An initial velocity of 6 m/s is given to a brick going down. What will be its final velocity after falling a 40 m distance?...