Classes are canceled due to snow, so you take advantage of the extra time to conduct some physics experiments. You fasten a large toy rocket to the back of a sled and take the modified sled to a large, flat, snowy field. You ignite the rocket and observe that the sled accelerates from rest in the forward direction at a rate of 11.5 m/s^2 for a time period of 3.30 s. After this time period, the rocket engine abruptly shuts off, and the sled subsequently undergoes a constant backward acceleration due to friction of 4.15 m/s^2.

Required:
a. After the rocket turns off, how much time does it take for the sled to come to a stop?
b. By the time the sled finally comes to a rest, how far has it traveled from its starting point?

Answer:

P = 24 watts

Explanation:

Given that,

Mass, m = 200 g = 0.2 kg

Velocity of the body, v = 120 m/s

We need to find the power of the body. The formula for power is given by :

P = Fv

Here, F = W (weight) i.e. mg

So,

P = 0.2 × 120

P = 24 Watts

So, the power of the body is 24 watts.

Answer:

Explanation:

Range R = 7 m

angle of projection θ = 40⁰

u² sin2θ / g = R where u is velocity of throw.

u² sin 80 / g = 7

u² = 69.71

u = 8.35 m/s

horizontal velocity = u cos 40 = 8.35 cos 40

= 6.4 m /s

vertical velocity = u sin 40 = 8.35 sin40

= 5.37 m /s

Maximum height :-

v² = u² - 2gh , u is initial vertical component of throw.

0 = 5.37² - 2 x 9.8 x h

h = 1.47 m

Time to reach max height :--

v = u - gt

o = 5.37 - 9.8 t

t = .55 s

Answer:

-75 cm

Explanation:

At l ; F = 350 Hz

At l + 15 cm ; F = 280 Hz

I = 350

I + 15 = 280

280I = 350(I + 15)

280I = 350I + 5250

280I - 350I = 5250

-70I = 5250

I = - 75cm

The length is - 75 cm

Answer:

I only know number 4 is correct

Explanation:

Answer:

Vf = 69.61 m/s

Explanation:

We will use the third equation of motion to solve this problem:

[tex]2gh = V_{f}^2 - V_{i}^2\\[/tex]

where,

g = acceleration due to gravity = 9.81 m/s²

h = height of cliff = 247 m

Vf = final velocity = ?

Vi = initial velocity = 0 m/s (boulder breaks loose from rest)

Therefore,

[tex](2)(9.81\ m/s^2)(247\ m) = V_{f}^2 - (0\ m/s)^2\\V_{f} = \sqrt{4846.14\ m^2/s^2}\\[/tex]

Vf = 69.61 m/s

Answer:

dude the answer is upright

Answer:

Aluminum and steel are good conductors of electricity.

Explanation:

1) All materials are good conductors of electricity.

This is false because nonmetal materials such as plastic or wood cannot conduct electricity.

2) Aluminum and steel are good conductors of electricity.

This is true. All metals are conductors of electricity.

3) Gold and wood are poor conductors of electricity.

This is false. Although gold can conduct electricity, wood can't.

4) Plastic and copper are good conductors of electricity.

This is false. Although copper can conduct electricity, plastic can't.

I hope this helps!

Answer:

B) Aluminum and steel are good conductors

Explanation:

Answer:

12164.4 Nm

Explanation:

CHECK THE ATTACHMENT

Given values are;

m1= 470 kg

x= 4m

m2= 75kg

Cm = center of mass

g= acceleration due to gravity= 9.82 m/s^2

The distance of centre of mass is x/2

Center of mass(1) = x/2

But x= 4 m

Then substitute, we have,

Center of mass(1) = 4/2 = 2m

We can find the total torque, through the summation of moments that comes from both the man and the beam.

τ = τ(1) + τ(2)

But

τ(1)= ( Center of m1 × m1 × g)= (2× 470× 9.81)

= 9221.4Nm

τ(2)= X * m2 * g = ( 4× 75 × 9.81)= 2943Nm

τ = τ(1) + τ(2)

= 9221.4Nm + 2943Nm

= 12164.4 Nm

Hence, the magnitude of the torque about the point where the beam is bolted into place is 12164.4 Nm

Answer: See explanation

Explanation:

From the information given in the question, the journal entry is written below:

Debit: Merchandise inventory 1960

Credit: Account payable 1960

(To record purchase)

Note that 1960 was gotten as:

= 2000 × 98%

= 2000 × 0.98

= 1960

Note that 2% discount was given.

Answer:

a) [tex]W=9810\: N[/tex]

b) [tex]F_{1}=251.14\: N[/tex]        

c) [tex]V_{g}=0.012\: m^{3}[/tex]

Explanation:

a)

El peso del cuerpo es:

[tex]W=mg[/tex]

g es la gravedad (9.81 m/s²)

[tex]W=1000*9.81[/tex]

[tex]W=9810\: N[/tex]

b)

Usando el principio de Pascal tenemos:

[tex]P_{1}=P_{2}[/tex]

y la presion es la fuerza sobre el area.

[tex]\frac{F_{1}}{A_{1}}=\frac{F_{2}}{A_{2}}[/tex]

Despejando F(1):

[tex]F_{1}=F_{2}\frac{A_{1}}{A_{2}}[/tex]

el area del plato es: [tex]A=\pi R^{2}[/tex]

[tex]F_{1}=F_{2}\frac{\pi R_{1}^{2}}{\pi R_{2}^{2}}[/tex]

[tex]F_{1}=F_{2}\frac{R_{1}^{2}}{R_{2}^{2}}[/tex]

F(2) es el peso del cuerpo de 1000 kg (W)

[tex]F_{1}=9810\frac{8^{2}}{50^{2}}[/tex]

Por lo tanto, la fuerza que se debe hacer es:

[tex]F_{1}=251.14\: N[/tex]          

c)

Como tenemos un sistema cerrado el volumen de agua que desciende por el embolo pequeño debe ser igual al que sube por el grande, por lo tanto:

[tex]V_{p}=V_{g}[/tex]

Vp es el volumen de agua en el émbolo pequeño

Vg es el volumen de agua en el émbolo grande

Como sabemos que son cilindros (V=πR²h)

[tex]\pi R^{2}h=V_{g}[/tex]

Entonces el volumen del émbolo mayor será:

[tex]V_{g}=\pi 0.08^{2}0.6[/tex]

[tex]V_{g}=0.012\: m^{3}[/tex]

Espero te haya sido de ayuda!

Answer:

[tex]\boxed{\text{\sf \Large 2.0 m/s^2 $}}[/tex]

Explanation:

Use acceleration formula

[tex]\displaystyle \text{$ \sf acceleration=\frac{change \ in\ velocity}{change \ in \ time} $}[/tex]

[tex]\displaystyle a=\frac{65-47}{12.0-3.0} =2.0[/tex]

Answer:

you have to times them all ti get the answer

Answer:

Kindly check explanation

Explanation:

Given the data:

Trial V (volts) I (mA)

1 1.00 7.2

2 2.10 14.0

3 3.10 20.7

4 4.00 27.2

5 4.90 32.2

Slope = Rise / Run

Rise = y2 - y1 = 32.2 - 7.2 = 25

Run = x2 - x1 = 4.9 - 1.0 = 3.9

Slope = 25 / 3.9 = 6.410

y = mx + c

The intercept, c

Take the point ( 1; 7.2)

Put x = 0

7.2 = 6.410(1) + C

7.2 - 6.410 = C

C = 0.79

Answer:

 A high pitch sound corresponds to a high frequency sound wave and a low pitch sound corresponds to a low frequency sound wave. I hope I got it correct !!

Answer:

something that can be burned to produce heat

Explanation:

Combustion can be defined as an exothermic chemical reaction between physical substances, usually in the presence of oxygen and hydrocarbons to produce heat, light and carbon.

A fuel can be defined as something that can be burned to produce heat.

In the process of heat conduction, thermal energy is usually transferred from fast moving particles to slow moving particles during the collision of these particles. Also, thermal energy is typically transferred between objects that has different degrees of temperature and materials (particles) that are directly in contact with each other but differ in their ability to accept or give up electrons.

Answer:

Explanation:

Hope this helps!

Answer:

1920Joules

Explanation:

The formula for calculating the kinetic energy of a body is expressed as;

KE = 1/2 mv²

m isthe mass

V is the speed

For the two masses, the combined KE is expressed as;

KE  = 1/2(m1+m2)v²

KE = 1/2(45+15)(8)²

KE  = 1/2 * 60 * 64

KE  = 30 * 64

KE  = 1920J

Hence the combined kinetic energy of the boy and the bicycle is 1920Joules

The combined kinetic energy of the boy and the bicycle is of 1920 J.

Given data:

The mass of boy is, m = 45.0 kg.

The mass of bicycle is, M = 15.0 kg.

The speed of bicycle is, v = 8.00 m/s.

The kinetic energy of an object is defined as the energy possessed by an object by virtue of motion of object. The combined kinetic energy of the boy-bicycle system is given as,

[tex]KE = \dfrac{1}{2}(m+M)v^{2}[/tex]

Solve by substituting the values as,

[tex]KE = \dfrac{1}{2}(45+15) \times 8^{2}\\\\KE = 1920 \;\rm J[/tex]

Thus, we can conclude that the combined kinetic energy of the boy and the bicycle is of 1920 J.

Learn more about the concept of kinetic energy here:

https://brainly.com/question/12669551

Answer:

Break down small pebbles and sediments, like sand

Break down large rocks like mountains

Explanation:

Answer:

Dakota moves a magnetic toy train toward a magnet that cannot move. What happens to the potential energy in the system of magnets during the movement? The potential energy increases because the train moves against the magnetic force. The potential energy decreases because the train moves against the magnetic force.

I hope this helps you :)

Answer:

Explanation:

Intensity of light is inversely proportional to distance from source

I ∝ 1 /r²  where I is intensity and r is distance from source . If I₁ and I₂ be intensity at distance r₁ and r₂ .

I₁ /I₂ = r₂² /r₁²

If r₂ = 4r₁ ( given )

I₁ / I₂ = (4r₁ )² / r₁²

= 16 r₁² / r₁²

I₁ / I₂ = 16

I₂ = I₁ / 16

So intensity will become 16 times less bright .

"16 times " is the answer .

Answer:

[tex]-18.43^{\circ}[/tex]

Explanation:

Let [tex]\theta[/tex] be the polar angle of −3i + j. We can find it using the formula as follows :

[tex]\tan\theta=\dfrac{y}{x}\\\\\tan\theta=\dfrac{1}{-3}\\\\\theta=\tan^{-1}(\dfrac{1}{-3})\\\\\theta=-18.43^{\circ}[/tex]

So, the required polar angle is [tex]-18.43^{\circ}[/tex].

Answer:

Gravitational

Tension

Normal

Friction.

Explanation:

The forces acting on the sled are:

Tension: the tension from the rope, this is the force that "moves" the sled.

Friction: kinetic friction between the sled and the ground as the sled moves.

There are another two forces that also act on the sled, but that "has no effect"

Gravitational force: This force pulls the sled down, against the floor.

Normal force: This force "opposes" to the gravitational one, so they cancel each other.

These two forces cancel each other, so they have no direct impact on the movement of the sled. BUT, the friction force depends on the weight of the moving object, and the weight of the moving object depends on the gravitational force, so we need gravitational force in order to have friction force.

Then we can conclude that the forces acting on the sled are:

Gravitational

Tension

Normal

Friction.

Answer:

 ΔV = -2.1 L

Explanation:

To solve this exercise we can use the ideal gas equation for two points

         PV = nRT

          P₁V₁ = P₂ V₂

where point 1 is on the surface and point 2 is at the desired depth,

          V₂ = [tex]\frac{P_1}{P_2} \ V_1[/tex]

let's calculate

           V₂ = ( [tex]\frac{1 atm}{2.5 atm}[/tex] ) 3.5 L

            V₂ = 1.4 L

this is the new volume, the change in volume is

          ΔV = V₂ -V₁

          ΔV = 1.4-3.5

          ΔV = -2.1 L

Answer:

conduction is the correct answer

Answer:

1.6 Hz

Explanation:

In simple harmonic motion, acceleration is given by the formula;

a = Aω²

Where;

A is amplitude

ω is angular velocity.

We are given A = 9.7 cm = 0.097 m

We know that acceleration due to gravity is 9.8 m/s².

Thus;

9.8 = 0.097ω²

ω² = 9.8/0.097

ω = √101.031

ω = 10.05 rad/s

Formula for frequency is;

f = ω/2π

Thus;

f = 10.05/2π

f = 1.6 Hz

Answer:

* roller skates and ice skates.

* roller coaster

Explanation:

One of the best examples for this situation is when we are skating, in the initial part we must create work with a force, it compensates to move, after this the external force stops working and we continue movements with kinetic energy, if there are some ramps, we can going up, where the kinetic energy is transformed into potential energy and when going down again it is transformed into kinetic energy. This is true for both roller skates and ice skates.

Another example is the roller coaster, in this case the motor creates work to increase the energy of the car by raising it, when it reaches the top the motor is disconnected, and all the movement is carried out with changes in kinetic and potential energy. In the upper part the energy is almost all potential, it only has the kinetic energy necessary to continue the movement and in the lower part it is all kinetic; At the end of the tour, the brakes are applied that bring about the non-conservative forces that decrease the mechanical energy, transforming it into heat.

Answer: 52 kg skydiver: 9.09 m/s and 522.55 s

              95 kg skydiver: 12.3 m/s and 386.2 s

Explanation: Drag Force is an opposite force when an object is moving in a fluid.

For skydivers, when falling through the air, the forces acting on it are gravitational and drag forces. At a certain point, drag force equals gravitational force, which is constant on any part of the planet, producing a net force that is zero. Since there is no net force, there is no acceleration and, consequently, velocity is constant. When that happens, the person reached the Terminal Velocity.

Drag Force and Velocity are proportional to the squared speed. So, terminal velocity is given by:

[tex]F_{G}=F_{D}[/tex]

[tex]mg=\frac{1}{2}C \rho Av_{T}^{2}[/tex]

[tex]v_{T}=\sqrt{\frac{2mg}{\rho CA} }[/tex]

where

m is mass in kg

g is acceleration due to gravitational force in m/s²

ρ is density of the fluid in kg/m³

C is drag coefficient

A is area of the object in the fluid in m²

Calculating:

The 52kg skydiver has terminal velocity of:

[tex]v_{T}=\sqrt{\frac{2(52)(9.8)}{(1.21)(0.7)(0.14)} }[/tex]

[tex]v_{T}=[/tex] 9.09

The 95kg skydiver's terminal velocity is

[tex]v_{T}=\sqrt{\frac{2(95)(9.8)}{(1.21)(0.7)(0.14)} }[/tex]

[tex]v_{T}=[/tex] 12.3

The 52 kg and 95kg skydivers' terminal velocity are 9.09m/s and 12.3m/s, respectively.

The time each one will reach the floor will be:

52 kg at 9.09 m/s:

[tex]t=\frac{4750}{9.09}[/tex]

t = 522.5

95 kg at 12.3 m/s:

[tex]t=\frac{4750}{12.3}[/tex]

t = 386.2

The 52 kg and 95kg skydivers' time to reach the floor are 522.5 s and 386.2 s, respectively.

Answer:

 K_a = 8,111 J

Explanation:

This is a collision exercise, let's define the system as formed by the two particles A and B, in this way the forces during the collision are internal and the moment is conserved

initial instant. Just before dropping the particles

          p₀ = 0

final moment

          p_f = m_a v_a + m_b v_b

          p₀ = p_f

          0 = m_a v_a + m_b v_b

tells us that

          m_a = 8 m_b

           0 = 8 m_b v_a + m_b v_b

           v_b = - 8 v_a                    (1)

indicate that the transfer is complete, therefore the kinematic energy is conserved

starting point

           Em₀ = K₀ = 73 J

final point. After separating the body

          Em_f = K_f = ½ m_a v_a² + ½ m_b v_b²

           K₀ = K_f

           73 = ½ m_a (v_a² + v_b² / 8)

we substitute equation 1

           73 = ½ m_a (v_a² + 8² v_a² / 8)

           73 = ½ m_a (9 v_a²)

           73/9 = ½ m_a (v_a²) = K_a

            K_a = 8,111 J