Vektor Posisi, Kecepatan dan Percepatan pada Gerak Parabola

Which is accelerating the most? (see photo)

In the photo, one apple and one orange are moving up while the other two fruits are moving down.

Which one the correct:

If you throw a stone horizontally out over the surface of a lake, the time it is in the air (i.e., before it hits the water) is determined only by?

A. the height from which you throw it.

B. the height from which you throw it and its initial speed.

C. its initial speed and the horizontal distance to the point where it splashes down.

SOLUTION As we've just learned, the horizontal and vertical components of a projectile's motion are independent. Therefore, the stone reaches the water at the same time as a rock that was dropped vertically from the same starting height. The time required for the stone to reach the water depends only on the height from which it is thrown, so answer A is the correct one. The distance the stone travels before splashing down, however, depends on both the height from which it is thrown and the speed with which it is thrown.

Independence of horizontal and vertical motion. In the vertical direction, a projectile behaves like a freely falling object; in the horizontal direction, it moves with constant velocity

Vektor Posisi dan Kecepatan pada Gerak Parabola

Vektor kecepatan : v = vx i + vy j

Kecepatan awal : v0 = v0x i + v0y j

Vektor posisi : r = x i + y j

arah sumbu x berlaku GLBB

arah sumbu y berlaku GLBB

Tinggi maksimum dan Jarak Maksimum pada Gerak Parabola

Tinggi maksimum dicapai pada saat kecepatan peluru searah sumbu y sama dengan nol.

Jarak maksimum dicapai saat posisi peluru searah sumbu y sama dengan nol.

Sebuah peluru ditembakkan dengan kecepatan awal: v0 = (100 i + 50 j) m/s dengan g = 10 m/s2. Tentukan:

a. Kecepatan peluru saat t = 4 s

b. Besar kecepatan dan sudut arah peluru

c. Posisi titik tertinggi

d. Posisi titik terjauh

Bahan bacaan:

College Physics.—9th. Ed. Sears & Zemansky’s. Hugh D. Young. Addison Wesley.
Fisika Dasar 2. Teori dan Implementasinya, untuk kelas XI SMA dan MA Program IPA. Budi Purwanto. Penerbit Tiga Serangkai. 2007