Sebuah senapan massanya 3 kg menembakkan peluru yang massanya 20 gram. Berapa kecepatan peluru lepas dari moncong senapan, jika setelah peluru ditembakkan senapan terpental ke belakang dengan kecepatan 0,5 m/s?

Sebuah senapan massanya 3 kg menembakkan peluru yang massanya 20 gram. Berapa kecepatan peluru lepas dari moncong senapan, jika setelah peluru ditembakkan senapan terpental ke belakang dengan kecepatan 0,5 m/s?

Jawaban untuk soal ini adalah 75 m/s

Hukum kekekalan momentum menyatakan bahwa momentum benda sebelum tumbukan memiliki nilai yang sama dengan momentum benda setelah tumbukan.

Diketahui:
ms = 3 kg = 3000 g
mp = 20 gr
vs = vp = v = 0 m/s
vs’ = -0,5 m/s, tanda (-) artinya benda mengarah ke belakang

Ditanyakan:
vp’

Penyelesaian:
Persamaan hukum kekekalan momentum
p awal = p akhir
ps + pp = ps’ + pp’
ms . v + mp . v = ms . vs’ + mp . vp’
3000 . 0 + 20 . 0 = 3000 . (-0,5) + 20 . vp’
0 + 0 = -1500 + 20vp’
1500 = 20vp’
vp’ = 75 m/s

jadi, kecepatan peluru tersebut adalah 75 m/s

Baca Juga :  How long were Hilda and her friends in the beach and its surrounding ? Dear Clara, How are you? Last Saturday I went on a nice trip with some friends. We went to a lovely beach about 30 kilometers from my town. We left on the bus at nine clock in the morning and arrived at the beach at ten. We spent the morning playing in the beach. We also made a castle from sand. Then, we had lunch in a small restaurant overlooking the beach. After lunch we climbed a large hill behind the beach and saw the beautiful view from the top. We got back to the bus around three clock and then we came back to town. What is your holiday experience? Please share with me. Sincerely yours, Hilda