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3 years ago

6

A weightlifter lifts a 250-kg mass 0.5 meters above his head, how much PEg does the mass have (Note: g=9.8 m/s2)? Round your ans

wer to the nearest whole number. J

2 answers:

morpeh [17]3 years ago

6 0

Answer:

1225 J

Explanation:

The Gravitational potential energy (PEG) gained by a mass lifted above the ground is given by

$PE=mgh$

where

m is the mass

g = 9.8 m/s^2 is the acceleration due to gravity

h is the height at which the object has been lifted

In this problem, we have

m = 250 kg

h = 0.5 m

So, the PE of the object is

$PE=(250 kg)(9.8 m/s^2)(0.5 m)=1225 J$

disa [49]3 years ago

4 0

Answer:

1225J

Explanation:

The Gravitational potential energy (PEG) gained by a mass lifted above the ground is given by

where

m is the mass

g = 9.8 m/s^2 is the acceleration due to gravity

h is the height at which the object has been lifted

In this problem, we have

m = 250 kg

h = 0.5 m

So, the PE of the object is

1225J

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I am Lyosha [343]

Answer:

9 meters

Explanation:

Given:

Mass of Avi is, $m=40\ kg$

Spring constant is, $k=176,400\ N/m$

Compression in the spring is, $x=20\ cm=0.20\ m$

Let the maximum height reached be 'h' m.

Now, as the spring is compressed, there is elastic potential energy stored in the spring. This elastic potential energy is transferred to Avi in the form of gravitational potential energy.

So, by law of conservation of energy, decrease in elastic potential energy is equal to increase in gravitational potential energy.

Decrease in elastic potential energy is given as:

$EPE=\frac{1}{2}kx^2\\EPE=\frac{1}{2}\times 176400\times (0.20)^2\\EPE=88200\times 0.04=3528\ J$

Now, increase in gravitational potential energy is given as:

$GPE=mgh=40\times 9.8\times h=392h$

Now, increase in gravitational potential energy is equal decrease in elastic potential energy. Therefore,

$392h=3528\\\\h=\frac{3528}{392}\\\\h=9\ m$

Therefore, Avi will reach a maximum height of 9 meters.

6 0

3 years ago

Power is the rate at which energy is transformed. A person is limited in the total work he or she can do only by the total energ

Sergio039 [100]

Answer:

Power is the rate at which energy is transformed.

The SI unit of power is the watt.

Power is the rate at which work is done.

Explanation:

In this question we have to choose the statements related to Power that are True.

In this sense, Power $P$ is the speed with which work $W$ is done. Its unit is Watts ( $W$ ), being $1 W=\frac{1 Joule}{1 s}$ .

Power is mathematically expressed as:

$P=\frac{W}{t}$

Where $t$ is the time during which work $W$ is performed.

On the other hand, the Work $W$ done by a Force $F$ refers to the release of potential energy from a body that is moved by the application of that force to overcome a resistance along a path. It is a scalar magnitude, and its unit in the International System of Units is the Joule (like energy). Therefore, 1 Joule is the work done by a force of 1 Newton when moving an object, in the direction of the force, along 1 meter ( $1J=(1N)(1m)=Nm$ ).

So, according to this explanation, the true statements are:

Power is the rate at which energy is transformed.

The SI unit of power is the watt.

Power is the rate at which work is done.

4 0

3 years ago

A girl runs and cover a distance of 200m in 20 secends.The speed of the girl is ................ m/s.

Mademuasel [1]

Speed = distance/time

Speed = (200m)/(20s)

Speed = 10 m/s

4 0

3 years ago

Rank in terms of momentum

eduard

Answer:

See the explanation below,

Explanation:

Momentum is defined as the product of mass by Velocity. In this way, we will replace the following equation in each of the cases.

$P=m*v$

where:

P = momentum [kg*m/s]

m = mass [kg]

v = velocity [m/s]

A)

$P = 10000*0\\P=0$

B)

$P=100*5\\P=500[kg*m/s]$

C)

$P=1200*15\\P=18000[kg*m/s]$

D)

$P=15*1000\\P=15000[kg*m/s]$

From higher to lower momentum

C,D,B,A

7 0

3 years ago

Boyle's Law states that as the pressure on a gas increases at constant temperature the volume of the gas

elena55 [62]

Boyle’s law is P1V1 = P2V2. This shows that pressure and volume have an inverse relationship, so increase in pressure causes a decrease in volume. B is your answer

4 0

3 years ago