Answer:
Combined kinetic energy =120 joules
Acceleration= [tex]10 m/s^2[/tex]
Explanation:
Given that the mass of the girl= 40 kg.
The mass of the boy= 40 kg.
The mass of the wagon = 20 kg.
The combined velocity of the boy and the wagon, v= 2.0 m/s.
The kinetic energy of any object having mass m and moving with the speed of v m/s, is
K.E.= [tex]\frac 1 2 mv^2[/tex].
Here, the combined mass of the boy and the wagon = 40 + 20 = 60 kg.
So, the combined kinetic energy of the boy and the wagon
[tex]=\frac 12 60 \times 2^2= 120[/tex] J
When a force is applied on the object having the mass m, then
F=ma,
where a is the acceleration produced in the object.
Here, F=500 newtons and m= 50 kg.
so, [tex]500=50\times a[/tex]
[tex]\Rightarrow a = 500/50=10 m/s^2[/tex].
Hence, the combined energy is 120 joules and the acceleration is 10 [tex]m/s^2[/tex].
