Question

Question Physics

A 35 kg girl is standing near and to the left of a 43 kg boy
on the frictionless surface of a frozen pond. The boy
tosses a 0.75 kg ice ball to the girl with a horizontal speed
of 6.2 m/s. What are the velocity of the boy and the girl
immediately after the girl catches the ice ball?
Girl
Boy
(1) 0.13 m/s left
0.11 m/s, right
(2) 0.17 m/s left 0.14 m/s, left
(3) 0.18 m/s right 0.13 m/s, left
(4) 0.42 m/s left 0.49 m/s, right​

$be \: brainly \: no \: spamming$
​

Answer 1

Given:

A 35 kg girl is standing near and to the left of a 43 kg boy on the frictionless surface of a frozen pond. The boy tosses a 0.75 kg ice ball to the girl with a horizontal speed of 6.2 m/s.

To find:

Final Velocity of Boy and Girl ?

Calculation:

Let's assume that velocity in rightward direction will be positive and vice-versa.

• Since tha ball is thrown by boy towards girl ,the ball travels towards left and hence its velocity will be considered negative.

Since, no external force acts on the system we can easily apply the principle of CONSERVATION OF LINEAR MOMENTUM:

When the boy tosses the ball:

$\therefore \: P1 = P2$

$\implies \: 0 + 0 = \{0.75 \times ( - 6.2) \} + 43v$

$\implies \: 0 = - 4.65 + 43v$

$\implies \: 43v = 4.65$

$\implies \: v \approx 0.11 \: m {s}^{ - 1}$

Since value of v is positive , we can say that boy moves 0.11 m/s rightwards.

When girl catches ball:

$\therefore \: P1 = P2$

$\implies \: \{0.75 \times ( - 6.2) \} + 0 = 0 + 35v$

$\implies \: - 4.65= 35v$

$\implies \: v = - 0.13 \: m {s}^{ - 1}$

Since , velocity of girl is negative , we can say that she moves with 0.13 m/s leftwards.