Q7, how the ans is 4.9 not 19.6?

We first apply the data to the problem.

Data:

[tex] \bold{\: \: \: \: \: \: \: \: \: \: \:V = 408km/h}[/tex]

[tex] \bold{ \: \: \: \: \: \: \: \: \: \: \: D = 80m} \\ \bold{T = ?}[/tex]

Now, we convert km/h to m/s.

Conversion:

[tex] \bold{408km/h * (1000m/1km) * (1h/3600s) }[/tex]

[tex] \bold{V = 113.3m/s}[/tex]

Then, we apply the formula that is.

Formula:

[tex] \bold{T = D/V}[/tex]

Finally we develop the problem.

Developing:

[tex] \bold{T = 80m / 113.3m/s}[/tex]

[tex] \bold{T = 0.706s}[/tex]

In a time of 0.706 seconds.

The work done in lifting the couch to the given height is 250 J.

The work done in lifting the couch is the product of the applied force and the displacement of the block.

Based on the law of conservation of energy, the work done in lifting the couch to the given height is equal to change in the gravitational potential energy of the couch.

P.E = mgh

P.E = Wh

where;

P.E = 50 N  x 5 m

P.E = 250 J

Learn more about work done here: https://brainly.com/question/25573309

#SPJ1

The complete question is below;

A 50n couch is lifted off the ground. How much work is done on the couch if it was lifted to a height of 5 m?

Answer:

25 J

Explanation:

Answer: The answer is 386 N

Explanation:

The apparent weight of the astronaut of mass 65.1 kg moving with a speed of 33.9 m/s in 2.7 s is 811.797 N.

Weight is the force with which a body is attracted toward the earth or a celestial body by gravitation and which is equal to the product of the mass and the local gravitational acceleration.

To calculate the astronaut's apparent weight, we use the formula below.

Formula:

Where:

From the question,

Given:

Substitute these values into equation 1

Hence, the apparent weight of the astronaut is 811.797 N.

Learn more about weight here: https://brainly.com/question/25973294

#SPJ1

Answer: B

Explanation:

You will have air resistance as a type of friction, and since there isn't a normal force opposing it, gravity will bring the ball toward the ground.

a) Work done by the tension force is obtained as 3.45 * 10^4  J

b) Work done by gravity is obtained as  2.94 * 10^4 J

In physics, the work done is referred to as the product of the force and the distance that have been covered by the force. We know that the work done by the tension force is the work that is done as the string is stretched across the distance as we have been given.

The work done by gravity is the work that is done as the mass is lifted across a height. Thus the work done is the work done when we lift the mass from one point to another.

In order to find the work done in each case;

a) Work done by the tension force = 1.38 ✕ 10^4 N * 2.50 m

= 3.45 * 10^4  J

b) Work done by the gravity = 1.20 ✕ 10^3 kg * 9.8 m/s^2 *  2.50 m

= 2.94 * 10^4 J

Learn more about work done:https://brainly.com/question/13662169

#SPJ1

Answer:

d

Explanation:

because when an object stand in front of light, light bends around the other and doesn't go through it

Based on the principle of moments. the distance from the end of the table should the box be placed before the board begins to tilt is 8.6 cm.

The distance from the end of the table should the box be placed before the board begins to tilt is determined from the principle of moments as follows:

The block is 30 cm on the table and 20 cm outside it.

The downward force acting on the left-hand side of the box = 3/5 x 5.50  = 3.3kg.

This force acts at the center of gravity, 15 cm or 0.15 m away.

Therefore, anticlockwise moments o the left side = 3.3 x 0.15 = 0.495 J

Also, the clockwise moment on the right side = Force * distance

Force = 2/5 x 5.5 = 2.2 N

Distance from the center of gravity = 10 cm or 0.10 m away.

the clockwise moment on the right side due to the board = 2.2 x 0.1 = 0.22.

The moment due to the box with a weight of 2.5 kg at a distance of x meters will be:

the total clockwise moment on the right side = 0.28 + 2.5 * x.

When the board is just about to tilt:

0.495 = 0.28 + 2.5 * x

2.5x = 0.495 - 0.28

x = 0.086 m or 8.6 cm

Learn more about the principle of moments at: https://brainly.com/question/28977824

#SPJ1

Pressure on the bottom of the barrel = 1.78 * 10⁵Pₐ

a) The force applied perpendicular to the object's surface and dispersed over the area is referred to as the pressure.

Given,

height of barrel = 0.8mP

density = 9800N/m²

atmospheric pressure = Pₙ = 1.013 * 10⁵Pₐ

From the relation,

Pressure at the bottom

Pₓ = Pₙ + pgh

Pₓ = 1.013 * 10⁵ + 9800 * 9.8 * 0.8

Pₓ = 1.78 * 10⁵Pₙ

b)

Given,

mass = 1kg

area, a =1.2cm² =1.2 * 10⁻⁴ m²

Gravitational acceleration g = 9.8m/s²

We know that

Pressure on the finger,

Pf = force/area

Pf = (mass*g) / a

Pf = (1 * 9.8)/ (1.2 * 10⁻⁴)

Pf = 8.17 * 10⁴ N/m²

a) pressure on the bottom = 1.78 * 10⁵Pₐ

b) pressure on the finger = 8.17 * 10⁴ N/m²

Learn more about pressure here:

https://brainly.com/question/29341536

#SPJ1

Answer:

Explanation:

Given:

V₀ = 8.06 m/s

V = 8.61 m/s

t = 5.00

________

a - ?

Acceleration:

a = (V - V₀) / t

a = (8.61 - 8.06) / 5.00 ≈ 0,11 m/s²

Answer:0.11

Explanation:

Answer: It can change its direction

Explanation:

Momentum is a vector, which has magnitude and direction.  An object can have the same speed and mass (magnitude) but if it changes direction, it just changed its momentum

At the bottom of the “ride,” when the jumper momentarily stops

Answer:

17,482.36 J

Explanation:

Ans. W = F •d cos  = 120 N • 165 m cos 28.0 = 17,482.36 J

Answer:

Explanation:

Given:

F = 330 N

h = 5 m

t = 2 s

_________

N - ?

N = A / t = F·h / t = 330·5 / 2 = 825 W

Answer:

Below

Explanation:

Acceleration   =   change in velocity  / change in time

(108 km/s  - 36 km/s)   / (10 s)   = 7.2 m/s^2

Robert pulls at a steady speed for 2m/s. She travelled 1200m in 10 minutes.

Speed = 2m/s

time taken = 10 minutes

(1 minute = 60 seconds )

then,

10 mint = 10 x 60 = 600 seconds

To calculate how far she travel we use :

distance travelled = speed x time

distance = 2 x 600

distance = 1200m

Robert pulls at a steady speed for 2m/s. She travelled 1200m in 10 minutes.

To know more about speed-time :

https://brainly.com/question/28238258

#SPJ1

The work done calculated is 92J.

Work is considered completed when a force produces motion. There are numerous aspects that affect how well a force performs. One of the aspects is the object's displacement in the force's direction. The second component is force. Work is referred to as the result of an object's displacement plus a force applied in the force's direction. Work is equal to F×S, where F represents force and S represents displacement. When a body is moved by a distance while being subjected to a force, the work done can be calculated by:

W= F×S

Given that,

Force applied= 40N

Displacement= 2.3m

So, on putting the given values in above equation,

W= 40×2.3

W= 92 J

Therefore, the answer is 92 Joule.

To know more about work done problems, visit:

https://brainly.com/question/16976412

#SPJ1

Answer:

Diver's dive depth 50 m

Explanation:

Given:

p = 5 bar = 5·10⁵ Pa  - Pressure

ρ = 1000 kg/m³ - Water density

g = 10 m/s²

______________

H - ?   Diver's dive depth

p = ρ·g·H

H = p/ ( ρ·g)

H = 5·10⁵ / (1000·10) = 50 m

Answer:s= A. 60 m/s

B. s=0 m/s

c. s=70 m/s

D. s=50.4 m/s

Explanation:

Sorry if its wrong

The qhantity of heat required to melt completely 200 g of lead is 62400 J.

Heat can be defined as a form of energy that brings about the sensation of warmth.

To find the quantity of heat required, we use the formula below.

Formula:

Where:

From the question,

Given:

Substitute these values into equation 1

Hence, the quantity of heat required is 62400 J.

Learn more about heat here: https://brainly.com/question/26306578

#SPJ1

MAIN ANSWER- [tex]5/\sqrt{21} sec[/tex]

supporting answer-When a body is moving, it experiences resistance because it interacts with its surroundings. This resistance is a friction force. Friction opposes relative motion between systems in contact but also allows us to move, a concept that becomes obvious if you try to walk on ice. Friction is a common yet complex force, and its behavior still not completely understood. Still, it is possible to understand the circumstances in which it behaves.

body of the answer- a block of mass m with 10kgs is sliding on a inclined plane with frictionless surface

final answer-5/\sqrt{21} sec

to learn more about wooden block of mass link

https://brainly.in/question/446426

#SPJ1

Answer:

Non-polar covalent bond

Explanation:

This type of covalent bond where electrons are shared equally between atoms is called a non-polar covalent bond.

Based on the size of the splash produced by the objects as a result of the force on the objects, object 4 most likely has the greatest mass.

The relationship between mass, acceleration, and force acting on an object is given by the equation below:

Force = mass * acceleration

Since the given object are allowed to fall under the influence, they are accelerated to the same extent.

Hence, the force on each object is proportional to its mass.

The greater the force, the greater the mass of the object.

Also, considering the splash produced by the objects; the greater the force, the greater will be the splash produced by the object.

Hence, object 4 has the greatest mass.

Learn more about mass and force at: https://brainly.com/question/2537310

#SPJ1

(a) The time of motion of the stone is 4.69 seconds.

(b) The maximum distance the trebuchet can be from the castle wall to be in range is 90.44 m.

(c) The maximum height reached by the stone is 26.95 m.

The time of motion of the stone is calculated as follows;

t = 2u sinθ / g

where;

t = (2 x 30 x sin50) / (9.8)

t = 4.69 seconds

The maximum distance the trebuchet can be from the castle wall to be in range is calculated as;

R = u²sin(2θ) / g

R = (30² sin(2 x 50))/(9.8)

R = 90.44 m

The maximum height reached by the stone is calculated as follows;

H = u² sin²θ / 2g

H = (30²  x (sin 50)²) / (2 x 9.8)

H = 26.95 m

Learn more about maximum height here: https://brainly.com/question/12446886

#SPJ1

The net distance and displacement traversed is 50m and  36.0555 m respectively.

Given - A man has walked 30m and 20m south and west respectively.

To find distance and displacement .

principle- Distance means path covered and a vector quantity. Displacement means shortest distance covered and state function. It is also scalar quantity. Displacement can be zero but distance can't be zero.

Total distance traversed= 30 + 20 = 50m

Total displacement traversed (s) ⇒√(x₁² + x₂²)

⇒√(30² + 20²)    ⇒√(900 + 400)

=√1300

=36.0555 m

To learn how to calculate displacement in detail-

https://brainly.com/question/15545775

#SPJ1

1.a. The reason of using half time is  an echo refers to the Reflection of sound after hitting the target just like a basket ball bouncing back as it hits its target i.e. earth.

So parameters like total energy , distance, amplitude of waves,.etc..  refers to the both action and reaction journey.

Like for example if a rubber ball travels 5m to hit the wall and returns back . so the net distance = incident distance + reflection distance⇒ 10m

But in Physics to compute the accurate result of incoming signals or energy perceived we just have to take either of the 2 journeys i.e. incidence or reflection. Second perception is the concept of taking average of multiple data. When there is 2 times i.e. one time to take incidence and other one is reflection , so in such cases average of the time for close vicinity of result.

1.b . The net distance propagated is 247.5 m.

Given - Sound travels 330m/s taking time 1.5s

To find the distance travelled -

distance travelled in 1 sec= 330 m

distance for 0.75 sec= 330 x 0.75 = 247.5m

Since 1.5 sec is the total time of the process of echo.

[tex]echo = incidence + reflection[/tex]

so taking time of one journey = 1.5 sec/ 2 = 0.75 sec

Hence the distance traversed is 247.5 m .

2. Dolphins uses echolocation as an ability or tool to perceive the incoming waves in atmosphere that includes sound waves.

They generate a special kind of sound that makes its target i.e. food to come to it.

Now talking about bats , although they also have similar ability of echolocation , but its mechanism to capture a food is time consuming comparatively and dolphins use higher frequencies compared to bats.

3.The length of time before the echo is received is 0.0001 sec.

Given - Speed = 1500m/s , distance =7.5cm ⇒0.075m

To find how long it will take before the receptance of incoming sound signal :-

[tex]2d=speed * time \\2d=vt[/tex]

[2 x 0.075]/ 1500= t

t= 0.0001 sec

so it takes 0.0001 sec to traverse before the echo is achieved.

To Refer more about echo-

https://brainly.com/question/29176444

#SPJ1

Answer: 9.8 N

Explanation:

A 20-minute cycle ergometer exercise at 60% VO2max has been demonstrated to dramatically improve impact for the majority of persons.

the property of being strongly felt or having a powerful impact: The explosion was so loud that it could be heard from five kilometres distant. Measures of luminosity. [C or U] the strength of being something that may be measured, such as sunlight, sound, etc.

A measure that is produced from a randomised measure is known as an intensity measure in probability theory. Since the randomised measure of a set's expected value is the intensity measure, which is a non-random measure, it equates to the average volume that the random measure assigns.

To know more about intensity visit:

https://brainly.com/question/17583145

#SPJ1

The quantity of 128 grams of chromium would be remaining.

The time required for half the reaction to change is called half life period.

This concept is useful for understanding carbon dating in Nuclear Physics. The term is used more to characterize any type of exponential decay. Nuclei that decay easily have shorter half life.

Given :- Half Life of Cr = 28 days

m= 510 grams

To find :- quantity of Cr after 56 days.

Formula : Nₙ= N₀/(2)ⁿ

Nₙ= 510/2²

Nₙ= 128g

Therefore 128 grams will be available after 56 days.

Understand more about Half life calculations:-

https://brainly.com/question/9216557