Mathematical and Physical Journal
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Problem G. 599. (April 2017)

G. 599. The acceleration of an object starting from rest at \(\displaystyle t_0=0\), and moving along a straight path, is \(\displaystyle 4~{\rm m/s}^2\). The magnitude of the acceleration of another object, undergoing uniform circular motion of radius 9 m, is also \(\displaystyle 4~{\rm m/s}^2\).

\(\displaystyle a)\) What is the instantaneous speed of each object at \(\displaystyle t_1=5\) s?

\(\displaystyle b)\) How much distance do they cover during the 5 s?

(3 pont)

Deadline expired on May 10, 2017.


Sorry, the solution is available only in Hungarian. Google translation

Megoldás. Az egyenes pályán gyorsuló test sebessége \(\displaystyle v_1=at_1= 20~\frac{\rm m}{\rm s}\), és \(\displaystyle s_1=\frac{a}{2} t_1^2=50~\)m utat tesz meg.

A körmozgást végző test sebessége a centripetális gyorsulás \(\displaystyle a=\frac{v_2^2}{R}\) képlete szerint

\(\displaystyle v_2= \sqrt{Ra}=\sqrt{(9~\rm m)(4~{\rm m/s}^2) }=6~\frac{\rm m}{\rm s},\)

és a megtett út: \(\displaystyle s_2=v_2t_1= 30~\)m.


Statistics:

28 students sent a solution.
3 points:Békési Péter, Bonifert Balázs, Csécsi Marcell, Csóti Kristóf, Fekete András Albert, Fialovszky Márk, Garamvölgyi István Attila, Geretovszky Anna, Horváth 999 Anikó, Kocsmár Martin, Kozmér Barbara, Miskolci Tamás, Pácsonyi Péter, Rusvai Miklós, Szakáll Lili, Takács Árpád, Tanner Norman, Tóth Lilla Eszter , Urbán István, Veres Kristóf, Vida Tamás, Virág Levente.
2 points:Holányi Zsófia, Kozák 023 Áron.
1 point:3 students.
0 point:1 student.

Problems in Physics of KöMaL, April 2017