Explain the meaning of work done and give examples

Answer:

C

Explanation:

horizintal speed stays same

only vertical speed changes

so H speed will stay 30 m/s

Built by 1800, it was the home of inventor Jethro Wood (1774-1834), whose 1819 invention of an iron moldboard plow revolutionized American agriculture.

Answer:

A hypothesis is a limited explanation of a phenomenon; a scientific theory is an in-depth explanation of the observed phenomenon. A law is a statement about an observed phenomenon or a unifying concept

Answer:

Explanation:

will try 2 explain fact, hypothesis, theory n law

fact is the starting pt: e.g. apple falls from tree

hypothesis tries 2 explain a fact: e.g. there is a force pulling down apple

theory is a complete explanation w/ equations n stuff: e.g. Newton came up w/ theory of gravitational attraction force

law is a theory dat has been proven right through tests n experiments: Newton's gravity theory had been proven right in many many tests.

Answer:

the magnitude of the average force on the bumper is 3189.8 N

Explanation:

Given the data in the question;

In terms of force and displacement, work done is;

W =[tex]F^>[/tex] × [tex]x^>[/tex]

W = [tex]Fxcos\theta[/tex]    ------- let this be equation 1

where F is force applied, x is displacement and θ is angle between force and displacement.

Now, since the displacement of the bumper and force acting on it is in the same direction,

hence, θ = 0°

we substitute into equation 1

W = [tex]Fxcos([/tex] 0° [tex])[/tex]

W = [tex]Fx[/tex] ------- let this be equation 2

Now, using work energy theorem,

total work done on the system is equal to the change in kinetic energy of the system.

[tex]W_{net[/tex] = ΔKE

= [tex]\frac{1}{2}[/tex]mv² -  [tex]\frac{1}{2}[/tex]mu² --------- let this be equation 3

where m is mass of object, v is final velocity, u is initial velocity.

from equation 2 and 3

[tex]Fx[/tex] = [tex]\frac{1}{2}[/tex]mv² -  [tex]\frac{1}{2}[/tex]mu²

we make F, the subject of formula

F = [tex]\frac{m}{2x}[/tex]( v² - u² )

given that mass of car m = 830 kg, x = 0.255 m, v = 0 m/s, and u = 1.4 m/s

so we substitute

F = [tex]\frac{830}{(2)(0.255)}[/tex]( (0)² - (1.4)² )

F = 1627.45098 ( 0 - 1.96 )

F = 1627.45098 ( - 1.96 )

F = -3189.8 N

The negative sign indicates that the direction of the force was in opposite compare to the direction of the velocity of the car.

Therefore, the magnitude of the average force on the bumper is 3189.8 N

Answer:

A. 6.13 x 107

Explanation:

Given the expression

5.92 x 10^7 + 2.11 x 10^6

First, we need to convert to the whole number

5.92 x 10^7 = 59200000

2.11 x 10^6 = 2110000

Add both values

59200000 + 2110000

= 61,310,000

Express in standard form

= 6.13 * 10^7

This gives the required result

Answer:

The actual speed of the rain is 5 m/s and its direction is -53.13°

Explanation:

The actual speed of the rain V = speed of man, v + speed of rain relative to man, v'.

V = v + v'

We add these vectorially.

Since the man's speed is 3 m/s east, in the positive x - direction, we have v = 3i  and the rain's speed is falling vertically at 4 m/s, in the negative y- direction, we have v' = -4j

So, V = v + v'

V = 3i + (-4j)

V = 3i - 4j

So, the magnitude of V which is its speed is V = √(3² + (-4)²) = √(9 + 16) = √25 = 5 m/s

The direction of V, Ф = tan⁻¹(vertical component/horizontal component) = tan⁻¹(-4/3) = tan⁻¹(-4/3) = tan⁻¹(-1.333) = -53.13°

So, the actual speed of the rain is 5 m/s and its direction is -53.13°

Explanation:

1. Distance, d = 5 m

Time, t = 10 s

Speed = distance/time

[tex]v=\dfrac{5}{10}=0.5\ m/s[/tex]

2. Mass, m = 10 kg

Acceleration, a = 3 m/s³

Force, F = mass (m) × acceleration (a)

F = 10 × 3

= 20 N

3. Mass, m = 7 kg

Height, h = 4 m

Potential energy, E = mgh

E = 7 × 9.8 × 4

E = 274.4 J

Hence, this is the required solution.

Answer:

venus......................

Answer:

0.444atm

Explanation:

Using the combined gas law equation;

P1V1/T1 = P2V2/T2

Where;

P1 = initial pressure (

P2 = final pressure (

V1 = initial volume (L)

V2 = final volume (L)

T1 = initial temperature (K)

T2 = final temperature (K)

According to this question,

P1 = 101.3 kPa = 101.3 × 0.00987 = 0.999atm

P2 = ?

V1 = 80L

V2 = 160L (double of V1)

T1 = 34°C = 34 + 273 = 307K

T2 = 0°C = 0 + 273 = 273K

Using P1V1/T1 = P2V2/T2

0.999 × 80/307 = P2 × 160/273

79.92/307 = 160P2/273

Cross multiply

307 × 160P2 = 79.92 × 273

49120P2 = 21818.16

P2 = 21818.16 ÷ 49120

P2 = 0.444

P2 = 0.444atm

Answer:

the other colours get absorbed by the paper

Answer:

The other colors are absorbed by the paper and not reflected.

Answer:

30 m

General Formulas and Concepts:

Energy

Gravitational Potential Energy: [tex]\displaystyle U_g = mgh[/tex]

Kinetic Energy: [tex]\displaystyle KE = \frac{1}{2}mv^2[/tex]

Law of Conservation of Energy

Explanation:

Step 1: Define

Identify variables

[Given] m = 0.8 kg

[Given] g = 10 m/s²

[Given] U = 240 J

[Solve] h

Step 2: Solve for h

Answer:

40479.6 J

Explanation:

Applying,

q = cm(t₂-t₁).................... Equation 1

Where q = change in heat content of the system, c = specific heat capacity of the system, m = mass of the system, t₁ = initial temperature, t₂ = final temperature.

From the question,

Given: m = 79 g = 0.079 kg, t₁ = 21°C, t₂ = 143°C

Constant: c = 4200 J/kg.°C

Substitute these values into equation 1

q = 4200(0.079)(143-21)

q = 331.8(122)

q = 40479.6 J

Answer:

[tex]I=0.902kg*m^2[/tex]

Explanation:

From the question we are told that:

Mass [tex]m=92.0kg[/tex]

Radius [tex]r=0.140m[/tex]

Generally the equation for moment of Inertia is mathematically given by

 [tex]I = 0.5*m*r^2[/tex]

 [tex]I=0.5*(92)*0.14^2[/tex]

 [tex]I=0.902kg*m^2[/tex]

Answer:

Energy Bill fluctuations are inevitable and depend on a variety of different factors. Two of the most important are the current weather your home is experiencing and the current price per Kilowatt Hour (which fluctuates more than you might think).

Answer:

Force = 1.632 Newton

Explanation:

Given the following data;

Pressure = 102 kPa

Area = 0.016 m²

To find what force the atmosphere exert on the palm of your hand;

Mathematically, pressure is given by the formula;

[tex] Pressure = \frac {Force}{area} [/tex]

Force = 102 * 0.016

Force = 1.632 Newton

Answer: 4800 N/m

Explanation:

Given

mass of rock [tex]m=2.5\ kg[/tex]

Height of cliff [tex]h=32\ m[/tex]

compression in the spring [tex]x=57\ cm[/tex]

Here, potential energy is converted into kinetic energy which in turn converts to elastic potential energy of the spring

[tex]\Rightarrow mgh=\dfrac{1}{2}kx^2\\\\\Rightarrow k=\dfrac{2mgh}{x^2}\\\\\Rightarrow k=\dfrac{1568}{0.3249}\\\\\Rightarrow k=4826.100\approx 4800\ N/m[/tex]

Answer:

480

Explanation:

2021

Answer:

V = 240V

Explanation:

V = I*R

V = 15A*16ohms

V = 240V

Answer:

The Distance traveled (in meters) by the jet as the observer watches the nose of the jet cross from one side of the moon to the other.

=145.5m

Explanation:

The radius of the circling jet r = 15.8km = 15.8*10^3 m

the angle subtended by moon

θ = 9.21*10^-3 rad

Therefore, the distance traveled by jet is

s = rθ

= (15.8*10^3 m)(9.21*10^-3 )

= (15,800)(0.00921)

=145.5m

Answer:

an unconscious needs rooted in childhood are the foundation of psychoanalytic theory.

Explanation:

Answer:

(a) 9.28 m/s2

(b) 9.03 m/s2

(c) 9.8 m/s2

(d) 450 N, 670 N

Explanation:

mass of elevator + student, m = 870 kg

Reading of scale, R = 450 N

(a) When the elevator goes down, the weight decreases.

Let the acceleration is a.

By the Newton's second law

m g - R = m a

870 x 9.8 - 450 = 870 a

a = 9.28 m/s2

(b) R = 670 N

Let the acceleration is a.

870 x 9.8 - 670 = 870 a

a = 9.03 m/s2

(c) If the scale reads zero, it mean the elevator is falling freely. The acceleration is downwards and its value is 9.8 m/s2.

(d) Tension in cable is 450 N and 670 N.

Answer:

  T = 9056 K

Explanation:

In the exercise they indicate that the body can be approximated by a black body, for which we can use the Wien displacement relation

                 λ T = 2,898 10⁻³

where lam is the wavelength of the maximum emission

                T = 2,898 10⁻³ /λ

let's calculate

                 T = 2,898 10⁻³ / 320 10⁻⁹

                  T = 9.056 10³ K

                  T = 9056 K

Answer:

Distance, S = 19.6 meters

Explanation:

Given the following data;

Time = 2 seconds

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

Also, the initial velocity of the object is equal to zero because it's starting from rest.

To find the total distance covered by the object, we would use the second equation of motion;

[tex] S = ut + \frac {1}{2}at^{2}[/tex]

Where;

Substituting into the equation, we have;

[tex] S = 0*2 + \frac {1}{2}*(9.8)*2^{2}[/tex]

[tex] S = 0 + 4.9*4[/tex]

[tex] S = 4.9*4 [/tex]

Distance, S = 19.6 meters

Therefore, the total distance covered by the object is 19.6 meters.

Answer:

Explanation:

The first thing we are asked to find is the Force experienced by the box. That is found in the formula:

F - f = ma where F is the force exerted by the box, f is the friction opposing the box, m is the mass, and a is the acceleration (NOT the same as the pull of gravity). But F can be rewritten in terms of the angle of inclination also:

[tex]wsin\theta-f=ma[/tex] where w is the weight of the box. We will use this version of the formula because it will help us answer the second question, which is to solve for a. Filling in:

First we need the weight of the box. Having the mass, we find the weight:

w = mg so

w = 25.14(10) so

w = 251.4 N (I am not paying any attention at all to the sig fig's here, since I noticed no one on this site does!) Now we have the weight. Filling that in:

251.4sin(30) - f = ma Before we go on to fill in for f, let's answer the first question. F = 251.4sin(30) so

F = 125.7   And in order to answer what a is equal to, we find f:

f = μ[tex]F_n[/tex] where Fn is the weight of the object.

f = .25(251.4) so

f = 62.85. Filling everything in now altogether to solve for a, the only missing value:

125.7 - 62.85 = 25.14a and

62.85 = 25.14a so

a = 2.5 m/s/s

Now we have to move on to another set of equations to answer the last part. The last part involves the y-dimension. In this dimension, what we know is that

a = -10 m/s/s

v₀ = 0 (it starts from rest)

Δx = -13.30 m (negative because the box falls this fr below the point fro which it started). Putting all that together in the equation for displacement:

Δx = v₀t + [tex]\frac{1}{2}at^2[/tex] and we are solving for time:

[tex]-13.30=0t+\frac{1}{2}(-10)t^2[/tex] and

[tex]t=\sqrt{\frac{2(-13.30)}{-10} }[/tex] so

t = 1.6 seconds to reach the bottom of the slope from 13.30 m high.

Answer:

C. S + 02 → S02

Explanation:

A synthesis or combination reaction is that reaction involving two elements as reactants to form a single compound as product.

In the reaction given below;

S + 02 → S02

Sulphur and oxygen are elemental substances that combine to synthesize sulfur IV oxide (SO2), and hence it is an example of synthesis reaction.

Answer:

171.5J

Explanation:

K=1/2 *m *U²

K=1/2 *7 *7²

K=171.5 J

Answer:

120 beats per minute.

Explanation:

If I take your pulse and observe 80 heartbeats in a minute. Then the period of your heartbeat is 0.8 s and frequency is 1.3Hz.

A pulse is the term used in medicine to describe the tactile arterial palpation of the cardiac cycle (heartbeat) by skilled fingertips. Any location where an artery can be compressed close to the surface of the body, such as the carotid artery in the neck, the radial artery in the wrist, the femoral artery in the groyne, the popliteal artery behind the knee, the posterior tibial artery near the ankle joint, and on the foot, can be used to palpate the pulse (dorsalis pedis artery). Heart rate may be determined by monitoring pulse, or the number of arterial pulses per minute. Auscultation, which is the process of counting the heartbeats while listening to the heart using a stethoscope, is another way to determine the heart rate. Typically, three fingers are used to gauge the radial pulse.

Given,

heart beat = 80 beats/min = 1.3 beats/s

Frequency is nothing but how much beats is heart having in one second and that is 1.3 beats/s. Hence frequency of heart is 1.3Hz.

The Period is reciprocal of frequency,

T = 1/f = 0.8 s

To know more about frequency :

https://brainly.com/question/29739263

#SPJ2.

Explanation:

No. From your own reference frame, nothing will change. Everything will look the same to you even if you're traveling at 99% speed of light. However, an outside observer will see you shrink to about 14% of your original length along the direction of your motion according to the Lorentz contraction predicted by special relativity:

[tex]L=L_{0} \sqrt{1 - \frac{v^2 }{c^2 }}[/tex]