a weight lifter lifts a 280-n set of weights from ground level to a position over his head, a vertical distance of 1.65 m. how much work does the weight lifter do, assuming he moves the weights at constant speed?

Answer:

1.876 J

Explanation:

First, let’s calculate the compression of the spring from the Hooke’s law:

F=kx,

here, F=75 N is the force acted on the spring, k=1500 N⁄m is the force constant of the spring, x is the compression of the spring.

Then, we get:

x=F/k=(75 N)/(1500 N/m)=0.05 m.

Finally, we can find the potential energy stored in the spring:

PE=1/2 kx^2=1/2∙1500 N/m∙(0.05 m)^2=1.875 J.

correct my answer if it's wrong ^^

Answer: lollllllllllllllllllllll

Explanation:

Answer:

1000 m

Explanation:

Given that,

The frequency of radio waves f = 300,000 Hz

We need to find the wavelength of these waves.

The formula to find wavelength is as follows :

[tex]c=f\lambda\\\\\lambda=\dfrac{c}{f}\\\\\lambda=\dfrac{3\times 10^8}{300000}\\\\\lambda=1000\ m[/tex]

So, the wavelength of these waves is 1000 m.

Answer:

C.Supersaturated

Explanation:

There are three types of solution:

SATURATED SOLUTION:

It is the solution that contains maximum amount of solute dissolved in a solution in normal conditions.  

UNSATURATED SOLUTION:

It is the solution that contains less than the maximum amount of solute dissolved in a solution in normal conditions. It has space for more solute to be dissolved in it.

SUPERSATURATED SOLUTION:

It contains more than the maximum amount of solute dissolved in it. Such a solution has no capacity to dissolve any more solute under any conditions.

Since the sugar is no more dissolving in the tea and has settled down. Therefore, the solution is:

C.Supersaturated

Answer:

B. Objects do not have to touch each other to experience a force.

Explanation:

For example ..One of the noncontact forces is magnetic force whereby a magnetic object will be attracted to another magnetic object of oppsite charged particles, through waves called electromagnetic waves. On the other hand, the two magnetic objects of similar charged particles can repel through electromagnetic waves..

Answer:

X-rays have so much energy they can go right through your muscles and fat.

Explanation:

There are actually more ways to fill in those two blanks... Different parts of the body absorb x-rays in varying degrees, but soft tissues (like skin, muscles, fat, and organs) allow most of the X-rays to pass through.

Answer:

I could help but i dont speak or understand a word of Arabic im so sorry.

Explanation:

Answer:

Displacement (km)

Explanation:

The y axis is the vertical axis pointing up and down. This is labeled as the the displacement (km) in the graph.

Answer:

C.1 is a waxing gibbous and 5 is a waning crescent.

Answer:

1, Coal,oil,natural gas,petroleum ...etc

2, -they pollute the environment

-In case of irresponsible use ,they can be

dangerous

-it is more reliable an renewable

Answer:

fire

Explanation:

burning the the oil

Answer:

1 m/s²

Explanation:

From the question,

Using

a = (v-u)/t.................... Equation 1

Where a = accelartion of the bicycle, v = Final velocity, u = initial velocity, t = time.

Given: v = 15 m/s, u = 5 m/s, t = 10 s

Substitute these values into equation 1

a = (15-5)/10

a = 10/10

a = 1 m/s²

Hence the acceleration of the bicycle is 1 m/s²

Explanation:

1. Low-energy particle detector: This particle detector measures the charged particles of the solar winds.

2. Magnetometer boom: This device measures magnetic fields produced by astronomical bodies.

3. High-gain antenna: A HGA has a narrow radio beam that is used to enhance the strength of signal. They simply amplify the weak signals.

4. Photopolarimeter: This is an instrument that is used to measure the strength and intensity and polarization of reflected light.

Answer:

what they said

Explanation:

Answer:

true

Explanation:

if all forces are equal then there would be no stronger force to give any net force so it would be zero

Answer:

hi

Explanation:

as a result of the collision of hot and cold air

hope it helps

have a nice day

Answer:

Hey mate.....

Explanation:

This is ur answer.....

Wind is the movement of air caused by the uneven heating of the Earth by the sun. ... Warm equatorial air rises higher into the atmosphere and migrates toward the poles. This is a low-pressure system. At the same time, cooler, denser air moves over Earth's surface toward the Equator to replace the heated air.

Hope it helps!

Brainliest pls!

Follow me! :)

Answer:

Magma from the core

Explanation:

...?

Answer:

[tex]343 \div 1000 = 0.343[/tex]

wavelength is equivalent to the velocity divided by the frequency

Answer:

work=f×d

GPE =m×g×h

[tex]kinetic energy = \frac{1}{2} mv {}^{2} \\ power = \frac{w}{t} [/tex]

Answer:

The energy stored is: 62.5 Joules

Explanation:

Given

[tex]k = 500N/m[/tex] --- spring constant

[tex]x = 0.5m[/tex] --- stretch

Required

The amount of energy

This is calculated as:

[tex]U = \frac{1}{2} kx^2[/tex]

[tex]U = \frac{1}{2} * 500N/m * (0.5m)^2[/tex]

[tex]U = 250N/m * (0.5m)^2[/tex]

[tex]U = 62.5\ J[/tex]

Answer:

A. 12,240.

Explanation:

1,530 times 8.0 = 12,240.

hope this helped :)

Answer:

Once you've had chickenpox you can't again.

Explanation: the virus remains inactive in your nerve tissue. Although it's unlikely you will get chickenpox again, the virus may reactivate later in life and cause a related condition called shingles.

Answer:

The difference between the sidereal and synodic months occurs becuase as our moon moves around the earth, the earth also moves around our sun. Our moon must travel a little farther in its path to make up for the added distance and complete the phase cycle.

Explanation:

Hope this helps.

Answer:

its the last question

Explanation:

Thats because erosion takes away stuff

Answer:

The average speed for the runner B for the first 25 seconds was;

30/25 = 1.2 m/s

Explanation:

The average speed of an object is given by the following formula

[tex]Average \ speed = \dfrac{Total \ distance \ covered}{Total \ time \ taken \ to \ cover \ the \ distance}[/tex]

From the graph, we have;

The coordinates of the runner B at the start = (0, 0)

The coordinates of the runner B after 25 seconds = (25, 30)

The total distance covered by the runner B after 25 seconds = The difference between the position at 25 seconds and the origin which is 30 meters

∴ The total distance covered by the runner B after 25 seconds = 30 meters

The time it takes the runner B to cover the distance = The 25 seconds

[tex]\therefore \ For \ the \ runner \ B, the \ average \ speed = \dfrac{30 \ meters}{25 \ seconds} = 1.2 \ m/s[/tex]

The average speed for the runner B for the first 25 seconds = 30 m/(25 s) = 1.2 m/s.

Answer: 88

Explanation:

Answer:

B. [tex]\frac{218}{85} At[/tex]

Explanation:

A P E X

The nucleus that completes the following equation is ²²⁶Ac₈₉

²²²Fr₈₇ →⁴He₂ +  ²²⁶Ac₈₉

Therefore the correct answer is option C.

The phenomenon of Radioactive decay is a type of nuclear reaction in which the unstable nucleus of a radioactive element lose energy in the form of nuclear radiation, some examples of radioactive decay are alpha decay, decay, and beta decay.

The complete equation for the nuclear reaction is

²²²Fr₈₇ →⁴He₂ +  ²²⁶Ac₈₉

For the given problem the nucleus completes the given equation is  ²²⁶Ac₈₉. The correct answer is option C.

learn more about radioactive decay

brainly.com/question/1770619

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