Question

A force of 20 N applied on two object of mass m1 & m2 accelerated by 10m/s² & 20 m/s² respectively. If both object tied together and same force applied then what is final acceleration?

a) 20/3 m/s²
b) 40/3 m/s²
c) 10/3 m/s²
d) None of these​

Answer 1

$b \: ) \: \frac{20}{3} \frac{m }{ {s}^{2} }$

Explanation:

the force applied= 20N

F=ma

20N = m1× 10 m/s²

20N/10 m/s²= m1

2 kg = m1

again

20N = m2× 20 m/ s²

20N/ 20 m/s² = m2

1kg = m2

if we consider both as a system the total mass becomes 1kg+2kg=3kg

the force applied is same

so from F= ma

we get 20N=3kg× a

20N/3kg=a

therefore 20/3 m/ s² is acceleration

Answer 2

• Force=F= 20 N
• Acceleration 1 = A1 = 10m/s²
• Acceleration 2 = A2 = 20 m/s²

${\boxed{\sf Mass=\dfrac{Force}{Acceleration}}}$

$\sf\longrightarrow M1 = \dfrac{F1}{A1}$

$\sf\longrightarrow M1=\dfrac{20}{10}$

$\sf\longrightarrow M1=2\;kg$

$\sf\longrightarrow M2=\dfrac{F2}{A2}$

$\sf\longrightarrow M2=\dfrac{20}{20}$

$\sf\longrightarrow M2=1\;kg$

If both object tied together and same force applied then

${\boxed{\sf Acceleration=\dfrac{Force}{Total\;Mass}}}$

$\sf\longrightarrow A=\dfrac{20}{1+2}$

$\sf\longrightarrow A=\dfrac{20}{3}$

Option A is correct mate.