Question

46. Two particles of masses 2 kg and 4 kg are thrown
from the top of a tower such that first is vertically
upward and second is at angle 45° above
horizontal. Acceleration of the centre of mass of
two particle system is
(1) g
2)g/6
(3) 2g/3
4) g/3​

Answer 1

answer : option (1) g

explanation : acceleration acting on both the particles are same and that is equal to acceleration due to gravity.

so, acceleration of particle of mass 2kg is $a_1$ = g

acceleration of particle of mass 4kg, $a_2$ = g

now, acceleration of centre of mass of two particles system is given as

$a_{cm}=\frac{m_1a_1+m_2a_2}{m_1+m_2}$

= $\frac{2\times g+4\times g}{2+4}$

= (2g + 4g)/6

= 6g/6

= g

hence, acceleration of centre of mass of system of particles = g

so, option (1) is correct choice.

Answer 2

Answer:

Option 1 i.e g

Explanation:

Given Two particles of masses 2 kg and 4 kg are thrown

from the top of a tower such that first is vertically

upward and second is at angle 45° above

horizontal. Acceleration of the centre of mass of

two particle system is

Now acceleration of both particles are same, which is equal to acceleration due to gravity.

So m1 = 2 kg , m2 = 4 kg

And a1 = g , a2 = g

Acceleration of centre of mass = m1a1 + m2a2 / m1 + m2

 = 2 x g + 4 x g / 2 + 4

 = 6 g / 6

Acceleration of centre of mass  = g