remidi fisika 2

8/8/2019 Remidi Fisika 2

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y M Arkham (17)

y Moh. Gani Ghanio (18)

y Moh Kosim (19)

y Nadiya Pranindita (20)y Natasya Ayu (21)


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1. Positons of Particle on a surface

Xaxis=iYaxis=j

Xaxis=iYaxis=j

The positions of a particle will express on surface in unit vectors

The positions of a particle on surface:

r =x i +y j

r =x i +y j


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r = r2 - r1

r =x i +yj

Where x=x2 x1y= y2 y1

r = r2 - r1

r =x i +yj

Where x=x2 x1y= y2 y1


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a. Average Velocity

Average velocity along a line straight:

= =

Average velocity on a surface :

= =

Where is the position at t = and is the position at t =

.


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The component form of the average velocity is

obtained by substituting with i + j .

where

and


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b. Instantaneous Velocity

Definiton ofinstantaneous velocity

Intanstantaneous velocity at t = is the slope of the

tangent line of position curve x-tat t = .

Intanstantaneous velocity is the first derivative

of position function x with respect to t.

c. Instantaneous velocity for straight-line motion


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Where:

d. Intanstantaneous velocity for motion on a plane

Instantaneous for straight-line motion

The i sta ta e s vel city at a y i t the c rve

f a articles traject ry is arallel t the ta ge t li e

f the traject ry at that i t.


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The components form of instantaneous velocityv isobtained by subtituting r =xi +yj into equation like that :

Where :

and


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e. Determining position from a velocity functionIf the velocity components and are known function of

time, then the horizontal position xand vertical positiony ofthe particle can be determined from equation below byintegrating it.


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a. Average acceleration

where is the velocity t= and is the velocity at t =

The components form average acceleation is obtainedby subtituting with in equation above.


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Where :

And


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b. Intantaneous acceleration as the slope of a v(t)graph

Definiton of intantaneous velocity

Intanstantaneous velocity at t = is the slope of the

tangent line of position curve x-tat t = .

Instantaneous acceleration is the first derivative of the

velocity function vwith the respect to t.


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c. Instantaneous acceleration for motions on a plane

and

Where :


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d. Determining velocity from a-t graph

If acceleration a as function of a time are known, then

velocityv can be determined by integrating :

So,


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1. A pitcher delivers a fast ball with a velocity of 43 m/s to thesouth. The batter hits the ball and gives it a velocity of51m/s to the north. What was the average acceleration ofthe ball during the 1.0ms when it was in contact with the

bat?answer:

acceleration = (vf- vi)/t = ( 51m/s to the north - 43 m/s tothe south) : (1.0x10-3s)

Letting south be positive and north negative yields

acceleration = ( -51m/s - 43 m/s ) : (1.0x10-3s) = -94000m/s/s

acceleration = 94000 m/s/s to the north


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2. You drive a car for 2.0 h at 40 km/h, then for another 2.0 h at60 km/h.

a. What is your average speed?b. Do you get the same answer if you drive 100 km at each of

the two speeds?

Answer:

a. The total distance driven = [(2 h )(40 km /h) + (2 h)( 60km/h)] = 200 kmThe total time = 2 + 2 = 4 h

average speed = (200 km)/(4 h) = 50km/h

b. total distance = 100 + 100 = 200 kmtotal time = [(100 km)/(40 km/h) + (100 km)/ 60 km/h)] = 4.17h

average speed = (200 km)/(4.17 h) = 48 km/h

remidi fisika 2

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