can someone please help

Answer:

0.18 m/s²

Explanation:

The total time taken to cover a 10 km race is 27 min, 43.6 seconds.

At 25 min, Pre was at 7.71 km mark. Therefore the average speed = 7.71 km / 25 min = 7710 m / (25 * 60) s = 5.14 m/s

The distance remaining = 10 km - 7.71 km = 2.29 km = 2290 m

The remaining time = 27 min, 43.6 seconds - 25 min = 2 min 43.6 second = 163.6 seconds

She accelerates for 60 seconds, therefore the distance covered (S) during the acceleration (a) is:

S₁ = 5.14(60) + 0.5a(60)² = 308.4 + 1800a

She maintains the speed for the remaining distance (S₂). The remaining time = 163.6 seconds - 60 seconds = 103.6 seconds. The final speed after the acceleration = (5.14 + 60a) m/s

S₂ = (5.14 + 60a)* 103.6 = 532.5 + 6216a

S₁ + S₂ = 2290 m

(308.4 + 1800a) + (532.5 + 6216a) = 2290

8016a + 840.9 = 2290

8016a = 1449.1

a = 0.18 m/s²

Answer:

Nitric acid, also known as aqua fortis and spirit of niter, is a highly corrosive mineral acid. The pure compound is colorless, but older samples tend to acquire a yellow cast due to decomposition into oxides of nitrogen and water. Most commercially available nitric acid has a concentration of 68% in water.

Explanation:

Good morning...

Nitric acid production is mainly driven by fertilizer industry. Nitric acid is used in the production of ammonium nitrate and calcium ammonium nitrate which find applications as fertilizers.

Answer:

D. Frequency

Explanation:

The energy of an  electromagnetic wave is proportional to frequency, mathematically it is expressed as;

E ∝ f

E = hf

where;

h is Planck's constant = 6.626 x 10⁻³⁴ Js

The equation above can also be expanded to;

[tex]E = hf = h \frac{c}{\lambda}[/tex]

where;

c is speed of light = 3 x 10⁸ m/s

λ is the wavelength of the electromagnetic wave

Since the speed of light is constant, we can conclude that the energy of the electromagnetic wave is directly proportional to its frequency and inversely proportional to its wavelength.

Therefore, the correct option for direct proportionality is FREQUENCY

The average velocity is 25 mph north.

Average velocity = displacement/time

Displacement =

(400 mi north) + (275 mi south)

Displacement = 125 mi north

Average V = (125 mi north) / 5 hours.

Average V = 25 mph north

Answer:

funny bone and compact bone

Explanation:

your funny bone only reacts if you hit it against something the compact bone is the heaviest and strongest bone in your body and the bone marrow is soft sponge like tissue in the center if most bones that produces white and red blood cells

Answer:

B= 4 A=5

Explanation:

multiplication of two vectors yields a vector oroduy

Answer:

Explanation:

You didn't fill in the proper masses which is why you never got an answer to this. But that's ok...I got you. I happen to know what they are! We will use the universal law of gravitation and the gravitational constant to solve this.

[tex]F_g=\frac{Gm_1m_2}{r^2}[/tex] and filling in:

[tex]F_g=\frac{(6.67*10^{-11})(5.98*10^{24})(7.36*10^{22})}{(3.84*10^8)^2}[/tex] The denominator is the radius of the earth plus the radius of the moon plus the distance between their surfaces, just FYI.

That gives us that

[tex]F_g=1.99*10^{20}N[/tex] Not sure what your choices entail, but I'd have to say, taking into consideration that maybe your problem didn't figure in the distance between the surfaces, you'd be at choice B.

Answer:

Explanation:

We need 2 different equations for this problem: first the velocity of sound equation, then the frequency of the sound equation.

The velocity of sound is found in:

v = 331.5 + .606T

We need to find that first in order to fill it into the frequency equation which is

[tex]f=\frac{v}{\lambda}[/tex] where v is the velocity we will find the part a, f is frequency and lambda is the wavelength. Starting with the velocity of the sound:

v = 331.5 + .606(25) and

v = 331.5 + 15 and rounding correctly using the rules for sig fig when adding:

v = 347 m/s

Filling that into the frequency equation:

[tex]75=\frac{347}{\lambda}[/tex] and

[tex]\lambda=\frac{347}{75}[/tex] so

[tex]\lambda=4.6m[/tex]

Explanation:

An oven thermostat regulates the temperature inside an oven. The thermostat's temperature-sensitive probe measures the oven's warmth, switching the heat on and off as necessary to maintain the correct temperature.

Answer:

44.1 m

Explanation:

Consider the displacement being x:

x = (g•t²)/2

x = (9.8•3²)/2

x = (9.8•9)/2

x = 88.2/2

x = 44.1 m

Answer:

Explanation:

that's the correct answer

Answer:

A temporary orbit in which a spacecraft awaits the next phase of its mission .

Answer:

It is connected in series with the circuit

Explanation:

This is because to measure the current in the circuit, the current in the circuit has to flow through the ammeter. As such, the ammeter must be connected in series with the circuit so as to measure the current flowing through the circuit.

So, to measure the current flowing through a circuit with an ammeter, the ammeter must be connected in series with the circuit.

Answer:

Explanation:

Force= (q1q2)/(4/\Ęr2)

3×10^6= (1.602×10^-19)^2/(r^2)

r^2=(2.27×10^-33)/(3×10^6)

r^2=8.55×10^-45

r= 9.25×10^-23

Answer: The energy incident on the solar panel during that day is [tex]9.24 \times 10^{7} J[/tex].

Explanation:

Given: Mass = 250 kg

Initial temperature = [tex]16^{o}C[/tex]

Final temperature = [tex]38^{o}C[/tex]

Specific heat capacity = 4200 [tex]J/kg^{o}C[/tex]

Formula used to calculate the energy is as follows.

[tex]q = m \times C \times (T_{2} - T_{1})[/tex]

where,

q = heat energy

m = mass of substance

C = specific heat capacity

[tex]T_{1}[/tex] = initial temperature

[tex]T_{2}[/tex] = final temperature

Substitute the values into above formula as follows.

[tex]q = 250 kg \times 4200 J/kg^{o}C \times (38 - 16)^{o}C\\= 250 kg \times 4200 J/kg^{o}C \times 22^{o}C[/tex]

As it is given that water absorbs 25% of the energy incident on the solar panel. Hence, energy incident on the solar panel can be calculated as follows.

[tex]\frac{25}{100} \times q = 250 kg \times 4200 J/kg^{o}C \times 22^{o}C\\q = 9.24 \times 10^{7} J[/tex]

Thus, we can conclude that the energy incident on the solar panel during that day is [tex]9.24 \times 10^{7} J[/tex].

Answer:

5m/sec^2

Explanation:

Distance=1200m

Time=4 min

1=60sec

4=4 x 60

=240sec

Velocity=Distance/Time

Velocity=1200/240

Velocity=5m/sec^2

Mark me as brainliest

Answer:

the power output P = 1484 W

Explanation:

Power P  = Force× speed

Given that motor of a battery-powered scooter can maintain a speed of 5.3 m/s by providing a force of 280 N.

Therefore,the power output of the motor P = 280×5.3 = 1484 W

Hence, the power output P = 1484 W

c- temperature

The speed of sound increases with increasing temperature .

Answer:

.04 kg m/s

Explanation:

Momentum is simply mass multiplied by velocity given by p = mv. You can consider momentum as mass in motion.

Before the collision, the data given for the toy train:

v = 0.5m/s

m = 75g

We need to convert grams into the SI unit of mass, kg.

75g / 1000g * 1kg = 0.075kg

Using p = mv, we can determine:

p = 0.075kg * 0.5m/s = 0.0375 kg m/s

Rounding to the value of 1 sig-fig, it comes out to be 0.04 kg m/s.

Answer:

SO

Explanation:

SI

Answer:

Explanation:

dynamic equilibrium

Answer:

increasing wavelength near beach

Explanation:

When wavelength increases, frequency of these waves decreases and the waves suddenly stop.

This is also called damped oscillation.

Answer:

I think C

Explanation:

If im right give brainliest :)

Answer:

Electricity is the set of physical phenomena associated with the presence and motion of matter that has a property of electric charge. Electricity is related to magnetism, both being part of the phenomenon of electromagnetism, as described by Maxwell's equations.

Answer:

it is maybe A but i'm not 100% sure

Explanation:

its the only one that is mixed

Answer:

Explanation:

The formula for the magnitude of this resultant vector, which is in Q1, btw, is:

[tex]B_{mag}=\sqrt{6.18^2+4.43^2}[/tex] which gives us, to 3 sig fig's:

7.60 m. Since the resultant vector is in Q1, we don't need to add anything to the angle once we find it to 3 sig fig:

[tex]tan^{-1}(\frac{4.43}{6.18})[/tex] gives us an angle of 35.6 degrees

Complete question:

(b) How much energy must be supplied to boil 2kg of water? providing that the specific latent heat of vaporization of water is 330 kJ/kg. The initial temperature of the water is 20 ⁰C

Answer:

The energy that must be supplied to boil the given mass of the water is 672,000 J

Explanation:

Given;

mass of water, m = 2 kg

heat of vaporization of water, L =  330 kJ/kg

initial temperature of water, t = 20 ⁰C

specific heat capacity of water, c = 4200 J/kg⁰C

Assuming no mass of the water is lost through vaporization, the energy needed to boil the given water is calculated as;

Q = mc(100 - 20)

Q = 2 x 4200 x (80)  

Q = 672,000 J

Q = 672,000 J

Q = 672,000 J

Therefore, the energy that must be supplied to boil the given mass of the water is 672,000 J

Answer:

Equal to the frictional force

Explanation:

Question; The options given with regards to a similar question posted online are;

A. Equal (equivalent) to the frictional force

B. Larger than the frictional force

C. Equal to the object's weight

D. More than the object's weight

Explanation

According to Newton's first law of motion, every object shall remain at rest or continue moving with uniform (constant speed) motion unless there is a net force acting on the object

Given that the velocity of the massive block, lying on the surface that has friction, being pulled by the rope = Constant

Therefore;

The net force acting on the moving block while being pulled by the rope = 0

From which we have;

The pulling force = The resistive force

Where;

The pulling force = The (pulling) force (applied) on the rope

The resistive force = The frictional force of the surface which tends to prevent the motion of the block

Therefore, given that the net force acting on the block = 0

The force on the rope = The frictional force (of the surface)

The correct option is option A. Equal to the frictional force.

Answer:

B

A

Explanation:

please mark as brainliest :)

Explanation:

these are quantities that have magnitude but no direction

Examples include : speed, mass, volume, density, everything, time