Answer:
You can increase your cardio respiratory endurance by exercising on the regular base that increase your heart beat and breathing rates. Some examples of good exercise is running, jumping rope, swimming dancing ect.
Explanation:
You are welcome.
Answer:
W= 4.4 J
Explanation
Elastic potential energy theory
If we have a spring of constant K to which a force F that produces a Δx deformation is applied, we apply Hooke's law:
F=K*x Formula (1): The force F applied to the spring is proportional to the deformation x of the spring.
As the force is variable to calculate the work we define an average force
Formula (2)
Ff: final force
Fi: initial force
The work done on the spring is :
W = Fa*Δx
Fa : average force
Δx : displacement
:Formula (3)
: final deformation
:initial deformation
Problem development
We calculate Ff and Fi , applying formula (1) :


We calculate average force applying formula (2):

We calculate the work done on the spring applying formula (3) : :
W= 11N*(0.7m-0.3m) = 11N*0.4m=4.4 N*m = 4.4 Joule = 4.4 J
Work done in stages
Work is the change of elastic potential energy (ΔEp)
W=ΔEp
ΔEp= Epf-Epi
Epf= final potential energy
Epi=initial potential energy




W=ΔEp= 5.39 J-0.99 J = 4.4J
:
The volume of the block of wood is given by length × width ×height
= 2.75 × 4.80 × 7.5
= 99 cm³
Density is given by mass/volume
Thus = 84.0 g/ 99 cm³
= 0.848 g/cm³
Hence; since the block is less dense than water (1 g/cm³) it will float
Dalton’s atomic theory proposed that all matter was composed of atoms