(a) The system of interest if the acceleration of the child in the wagon is to be calculated are the wagon and the children outside the wagon.
(b) The acceleration of the child-wagon system is 0.33 m/s².
(c) Acceleration of the child-wagon system is zero when the frictional force is 21 N.
<h3>
Net force on the third child</h3>
Apply Newton's second law of motion;
∑F = ma
where;
- ∑F is net force
- m is mass of the third child
- a is acceleration of the third child
∑F = 96 N - 75 N - 12 N = 9 N
Thus, the system of interest if the acceleration of the child in the wagon is to be calculated are;
- the wagon
- the children outside the wagon
<h3>Free body diagram</h3>
→ → Ф ←
1st child friction wagon 2nd child
<h3>Acceleration of the child and wagon system</h3>
a = ∑F/m
a = 9 N / 27 kg
a = 0.33 m/s²
<h3>When the frictional force is 21 N</h3>
∑F = 96 N - 75 N - 21 N = 0 N
a = ∑F/m
a = 0/27 kg
a = 0 m/s²
Learn more about net force here: brainly.com/question/14361879
#SPJ1
Answer:
b) twice the energy of each photon of the red light.
Explanation:
= Wavelength
h = Planck's constant = 
c = Speed of light = 
Energy of a photon is given by

Let
= 700 nm

For red light

For UV light

Dividing the equations

Hence, the answer is b) twice the energy of each photon of the red light.
Answer:
Advantages: In small quantities they help your body produce vitamin D.
Disadvantages: They can cause sunburn or even skin cancer if used in large quantities.
Explanation:
Answer:
B. As the temperature increases, the kinetic energy of the molecules increases.
Explanation:
When the temperature of an object increases, the kinetic energy of its particles increases, so the thermal energy of an object increases as its temperature increases.
D, 0.140 liters! Hang on a sec and I'll show you a trick I use.