Plz! How to solve this question? The answer is B.

10. when creating a cardiovascular fitness routine which program would be appropriate?

sasho [114]

Answer:

10. B

13. It's actually 30 seconds but 20 comes closest so B

14. B, any type of stretching is good before you perform any type of physical activity because it loosens up the muscles

15. D, all of the above

Explanation:

I have done many sports in my life and am still very active, I grew to know most of these things through the years.

5 0

3 years ago

A particle of mass moves under a force given bywhere and are unit vectors in the and directions. The particle is placed at the o

krek1111 [17]

The elapsed time when the particle returns to the origin is determined from the ratio of initial velocity and acceleration of the particle.

<h3>Time of motion of the particle</h3>

The time of motion of the particle is calculated by applying Newton's second law of motion.

F = ma

F = m(v)/t

where;

t is time of motion of the particle
m is mass of the particle
v is velocity of the particle

a = v - u/t

v = u + at

when the particle returns to the origin, direction of u, = negative.

final velocity = 0

0 = -u + at

at = u

t = u/a

Learn more about force here: brainly.com/question/12970081

#SPJ11

4 0

2 years ago

Describe seven physical properties that help distin- guish one mineral from another.

Lilit [14]

Answer:

Color, Streak, luster, cleavage and fracture, hardness, crystal shape, and density.

Explanation:

6 0

3 years ago

Consider the classic problem with holiday lights, one little bulb goes out and the whole string goes out. First consider a strin

Flura [38]

Answer:

a. 0.33 Amp

b. 2.4 Volt

c. 0

d. 2.45 Amp

e. Infinite

f. Series is safer

Explanation:

Series Connection of Resistors

When two or more resistors are connected in series, the current through each one of them is the same, and the voltage divides depending on the particular value of each resistance. If all the resistances are equal, then the voltage is equally divided.

a. The string of 50 bulbs is connected to a 120 VAC outlet and consumes 40 W. The power of a circuit is given by

$P=V.I$

Solving for I

$\displaystyle I=\frac{P}{V}=\frac{40}{120}=0.33\ Amp$

Since all the bulbs are connected in series the current is the same for all of them.

b. The voltage is equally divided, so each bulb has 120/50= 2.4 V

c. If one of the bulbs burns out and its resistance becomes infinite, then the series circuit is open and no current flows through it, neither through the rest of the bulbs. The typical case of the whole string going out.

d. If one of the bulbs short circuits, the resistance of that bulb is zero and the voltage is distributed by the 49 remaining bulbs. Thus the new current is

$\displaystyle I=\frac{V}{R}=\frac{120}{49}=2.45\ A$

e. If the bulbs were connected in parallel, all of them would have the same voltage, and the total current will be equally divided among them. In that case, a short circuit in one of the bulbs will cause a parallel short, theoretically producing an infinite current and making the short circuit protection blow up.

f. The condition described above makes the strings be made of series-connected bulbs which is safer than the parallel circuit. If a single bulb shorts, the entire string goes out in a series connection, but the breaker would trigger disconnection of the house circuit if it's a parallel connection. That is why we must deal with unusable strings instead of burning cables.

6 0

3 years ago

An airplane of mass 1.60 ✕ 104 kg is moving at 66.0 m/s. The pilot then increases the engine's thrust to 7.70 ✕ 104 N. The resis

Ivan

(a) No, because the mechanical energy is not conserved

Explanation:

The work-energy theorem states that the work done by the engine on the airplane is equal to the gain in kinetic energy of the plane:

$W=\Delta K$ (1)

However, this theorem is only valid if there are no non-conservative forces acting on the plane. However, in this case there is air resistance acting on the plane: this means that the work-energy theorem is no longer valid, because the mechanical energy is not conserved.

Therefore, eq. (1) can be rewritten as

$W=\Delta K + E_{lost}$

which means that the work done by the engine (W) is used partially to increase the kinetic energy of the airplane ( $\Delta K$ ) and part is lost because of the air resistance ( $E_{lost}$ ).

(b) 77.8 m/s

First of all, we need to calculate the net force acting on the plane, which is equal to the difference between the thrust force and the air resistance:

$F=7.70\cdot 10^4 N - 5.00 \cdot 10^4 N=2.70\cdot 10^4 N$