ELFT HÍRADÓ

[Banyasz Istvan <banyasz.istvan AT wigner.hu>]

Dear Colleagues,

I published the following simple kinematic problem on Fizinfo in June 
2024.

There were quite a number of responses. Some colleagues claimed that the 
problem was not well defined because the position of the Japanese 
submarine could be anywhere on a circle of a radius of 10 km around the 
battleship. They were right.

I finally decided to publish an amended verison of the problem.

I have made the correction to the original text cited below.

The added text is in capital letters.


Dr. István Bányász


Department of Materials Science by Nuclear Methods
Wigner Research Centre for Physics of the H.A.S.

Phone: +3613922222 Exts 1506 and 1732
Cellular: +36308847750

Skype name:

luzdivino

Mailing address:
Budapest
P.O.B. 49
H-1525 Hungary

Mailing packets to:

Dr. István Bányász
Wigner Research Centre for Physics
Konkoly-Thege út 29-33
Budapest
H-1121
Hungary

---------- Forwarded message ----------
Date: Sun, 30 Jun 2024 21:36:38 +0200 (CEST)
From: Banyasz Istvan <banyasz.istvan AT wigner.hu>
To: fizinfo <fizinfo AT lists.kfki.hu>
Subject: Kinematic problem to be solved

Dear Colleagues,

Here is a simple problem to be solved:

Solve the following problem:

The Task Force of the British Royal Navy was cruising home to Singapore on 
the South China Sea after having not been able to impede the invasion of 
Malaysia by the Imperial Japanese Army and Navy on 10 December 1941.

Submarine I-58 of the Imperial Japanese Navy spotted the convoy at 03:40. 
She was at a distance of 10 km from the Repulse battleship at that moment. 
After having received permission to engage, submarine I-58 surfaced and 
prepared for battle.

Maintaining the separation of 10 km from Repulse, the submarine began 
cruising at the same course and speed as Repulse. Speed of both vessels 
was 40 km/h. THE LINE SEGMENT CONNECTING THE TWO VESSELS WAS PERPENDICULAR 
TO THEIR COMMON VELOCITY.

The submarine I-58 fired no fewer than 5 Type 90 torpedoes at the 
battleship. At what angle did the torpedoes have to be fired in relation 
to the submarine's direction of travel in order to hit the battleship, if 
the speed of the torpedos was 70 km/h? (Suppose that Repulse did not make 
evasive maneuvers in the meantime.) Ignore drag and and possible sea 
currents.

(The Repulse and the battleship Prince of Wales were sunk by Japanese bombers
and torpedo bombers in the subsequent sea battle.)

PREPARE A DRAWING!


5Dr. István Bányász


Department of Materials Science by Nuclear Methods
Wigner Research Centre for Physics of the H.A.S.

Phone: +3613922222 Exts 1506 and 1732
Cellular: +36308847750

Skype name:

luzdivino

Mailing address:
Budapest
P.O.B. 49
H-1525 Hungary

Mailing packets to:

Dr. István Bányász
Wigner Research Centre for Physics
Konkoly-Thege út 29-33
Budapest
H-1121
Hungary