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2 years ago

Suppose you lift a 20 kg box by a height of 1.0 m.

2 answers:

8 0

Answer: The work done in lifting something is W=mgh where m is the mass of the objet, g is the gravity acceleration and h is the height, this work is done because you are "fighting" against the force of gravity.

so in this case we have W = 20kg*9.8m/s*1m= 196N

9966 [12]2 years ago

6 0

W=mgh W=(20)(9.8)(1) w=196J

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What is kinematics?<br>explain!!~<br><br>thankyou ~

Hatshy [7]

Answer:

<u>Kinematics:-</u>

Branch of mechanics concerned
Features of motion in an object
Causes and effects of motions

Hope it helps!

6 0

2 years ago

Read 2 more answers

Two particles with oppositely signed charges nC are placed at two of the vertices of an equilateral triangle with side length 3

babymother [125]

The magnitude of the electric field at the third vertex of the triangle is determined as zero.

<h3>Electric field at the third vertex of the triangle </h3>

The electric field at the third vertex of the equilateral triangle due to the other charges placed on the first and second vertices is calculated as follows;

E = E(13) + E(23)

E = (kq₁)/r² + (kq₂)/r²

where;

q1 is positive charge
q2 is negative charge

E = (kq₁)/r² - (kq₂)/r²

E = 0

Thus, the magnitude of the electric field at the third vertex of the triangle is determined as zero.

Learn more about electric field here: brainly.com/question/14372859

#SPJ1

5 0

1 year ago

Cellular phones use _____?

dangina [55]

Let's see: frequency of cellular phone waves (GSM phones) is (800-1900 MHz). If we look at the table of the electromagnetic spectrum, we can see that this range is contained within the frequencies of the microwaves, which include waves in the range 300 MHz-300 GHz.

So, summarizing, the correct answer is "microwaves".

3 0

2 years ago

Read 2 more answers

An oven uses 4500 watts of power in 2 minutes, how much work was done?

jolli1 [7]

First of all we state the formula
Power=work done/time
we can rearrange this formula as well
work done=power x time

Since the SI unit of time is in seconds we change the minutes to seconds
2mins= 60x2 = 120 seconds

Using our formula (work done=power x time) we simply put in the values
work done = 4500 x 120
work done = 540,000J

4 0

2 years ago

A large airplane typically has three sets of wheels: one at the front and two farther back, one on each side under the wings. Co

Tems11 [23]

(a) The force the ground exerts on each set of rear wheels when the plane is at rest on the runway is 0.743 MN.

(b) The force the ground exerts on the front set of wheels is 0.239 MN.

<h3>Center mass of the airplane</h3>

The concept of center mass of an object can be used to dtermine the mass distribution of the airplane along the line through the center.

<h3>Some assumptions</h3>

The wheels under the wind do not pass through the center line.
The position of the front wheel is constant and it is zero mark (origin).
The rear wheels are at 21.7 m mark

Position of the center mass of the plane is calculated as follows;

Let the position of the center mass, Xcm = y

the center mass is 3 m in front of rear wheels, that is

21.7 - y = 3

y = 21.7 - 3

y = 18.7 m

Xcm = 18.7 m

<h3>Mass of the plane at the position of the rear wheels</h3>

Let the mass of the plane at front wheels = M1

Let the mass of the plane at rear wheels = M2

$X_{cm} = \frac{M_1x_1 + M_2x_2}{M_1 + M_2}$

$18.7 = \frac{M_1(0) + M_2(21.7)}{177000} \\\\3,309,900 = 21.7M_2\\\\M_2 = \frac{3,309,900}{21.7} \\\\M_2 = 152,529.95 \ kg$

<h3>Force exerted by the ground on each rear wheel</h3>

There are two rear wheels, and the force exerted on each wheel due to mass of the airplane at this position is calculated as follows;

$W = mg\\\\W_1 = W_2 = \frac{1}{2} (mg) = \frac{1}{2} (152,529.95 \times 9.8) = 743,396.76 \ N= 0.743 \ MN$

<h3>Mass of the plane at the position of the front wheel</h3>

M1 + M2 = 177,000

M1 = 177,000 - M2

M1 = 177,000 - 152,529.95

M1 = 24,470.05 kg

<h3>Force exerted by the ground on the front wheel</h3>

W = mg

W = 24,470.05 x 9.8

W = 239,806.5 N = 0.239 MN

Learn more about center mass here: brainly.com/question/13499822

7 0

1 year ago