Remidi Fisika 2
-
Upload
natasya-ayu-ningrum -
Category
Documents
-
view
232 -
download
0
Transcript of Remidi Fisika 2
-
8/8/2019 Remidi Fisika 2
1/17
-
8/8/2019 Remidi Fisika 2
2/17
y M Arkham (17)
y Moh. Gani Ghanio (18)
y Moh Kosim (19)
y Nadiya Pranindita (20)y Natasya Ayu (21)
-
8/8/2019 Remidi Fisika 2
3/17
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
-
8/8/2019 Remidi Fisika 2
4/17
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
-
8/8/2019 Remidi Fisika 2
5/17
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 =
.
-
8/8/2019 Remidi Fisika 2
6/17
The component form of the average velocity is
obtained by substituting with i + j .
where
and
-
8/8/2019 Remidi Fisika 2
7/17
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
-
8/8/2019 Remidi Fisika 2
8/17
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.
-
8/8/2019 Remidi Fisika 2
9/17
The components form of instantaneous velocityv isobtained by subtituting r =xi +yj into equation like that :
Where :
and
-
8/8/2019 Remidi Fisika 2
10/17
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.
-
8/8/2019 Remidi Fisika 2
11/17
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.
-
8/8/2019 Remidi Fisika 2
12/17
Where :
And
-
8/8/2019 Remidi Fisika 2
13/17
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.
-
8/8/2019 Remidi Fisika 2
14/17
c. Instantaneous acceleration for motions on a plane
and
Where :
-
8/8/2019 Remidi Fisika 2
15/17
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,
-
8/8/2019 Remidi Fisika 2
16/17
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
-
8/8/2019 Remidi Fisika 2
17/17
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