Answer:
The mass is [tex]m_1 = 3m[/tex]
Explanation:
Generally from Newton law for the first block
[tex]F = ma[/tex]
=> [tex]a = \frac{F}{m}[/tex]
For the second block the force is [tex]F_1 = 2F[/tex] and the acceleration is [tex]a_1 = \frac{2a}{3}[/tex]
So from Newton law
[tex]2F = m_1*\frac{2a}{3} [/tex]
=> [tex] 3F = m_1 * a[/tex]
substituting for a
=> [tex] 3F = m_1 * \frac{F}{m} [/tex]
=> [tex]m_1 = 3m[/tex]