Answer:
a= 17.877 m/s² : Magnitude of the acceleration of the flea
β = 88.21° : Direction of the acceleration of the flea
Explanation:
Conceptual analysis
We apply Newton's second law:
∑F = m*a (Formula 1)
∑F : algebraic sum of the forces in Newton (N)
m : mass in kilograms (kg)
a : acceleration in meters over second square (m/s²)
Problem development
Look at the flea free body diagram in the attached graphic
The acceleration is presented in the direction of the resultant force (R) applied over the flea .


R= 10.905*10⁻⁶ N
We apply the formula (1) to calculate the magnitude of the acceleration of the flea
∑F = m*a m = 6.1 * 10⁻⁷ kg
R = m*a
a= R/m
a= (10.905*10⁻⁶) / (6.1 * 10⁻⁷ )
a= 17.877 m/s²
β: Direction and magnitude of the acceleration of the flea


β = 88.21°
Answer: False
When the diaphragm
contracts, the muscles will also contract and pull upward and increase the size
of the thoracic cavity thus decreases air pressure inside during inspiration. After
the diaphragm contracts, it goes to relaxation, the muscles will also relaxed. It
gets looser and return to its original position higher up in the chest. This increase
the pressure in the chest, which force the air in the lungs out through the
nose.
Change in thermal energy = mass × specific heat capacity × change in temperature.
Answer: you would need to know the mass of each mug