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3 years ago

A weightlifter raises a 50kg weight to a height of 2m in 2 minutes. What was the power spent by the weightlifter?

Physics

1 answer:

belka [17]3 years ago

8 0

Answer:

117.72kW

Explanation:

Given data

Mass m= 50kg

height x = 2m

time taken = 2 minutes= 129 seconds

let us find the work done

WD= force * distance

WD= mgx

WD= 50*9.81*2

WD= 981 Joules

Let us find the power

Power= work * time

Power= 981*120

Power= 117720

Power= 117.72 kW

Hence the power spent is 117.72kW

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Block 1, of mass m1

musickatia [10]

Answer:

M2=0.52kg

Explanation:

thats rightt

7 0

3 years ago

a plane is flying 120 m above the ground at an angle of 30 degrees to the horizontal, when the pilot released 2 fuel tanks to de

charle [14.2K]

Answer:

2.26 seconds

97m/s

Explanation:

1. Fall time

i) Find the vertical speed of the plane when the tanks were released

$V_{y,0}=84m/s\times sin(30\º)=42m/s$

That is the same initial vertical speed of the tanks.

ii) Find the fall time

$y-y_0=V_{y,0}\cdot t+g\cdot t^2/2$

$120=42t+4.9t^2$

$4.9t^2+42t-120=0$

$t=\dfrac{-42\pm\sqrt{(42)^2-4(4.9)(-120)}}{2\times 4.9}$

Only the positive value has aphysical meaning: t = 2.26 seconds.

2. Speed when they hit the ground

i) The horizontal speed is constant:

$V_x=84m/s\times cos(30\º)\approx72.5m/s$

ii) The vertical speed is:

$V_y=V_{y,0}+g\cdot t$

$V_y=42m/s+9.8m/s^2\cdot (2.26s)\approx64.1m/s$

iii) Total speed

$V=\sqrt{V_x^2+V_y^2}$

$V=\sqrt{(72.5m/s)^2+(64.1m/s)^2}\approx97m/s$

6 0

4 years ago

Which of the following scenarios would cause a sound to stop being produced?

ra1l [238]

The scenario that would cause a sound to stop being produced is when a molecule moves through its normal position to the opposite side of its normal position. The answer is letter A. This is also known as destructive interference.

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4 years ago

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If different groups of scientist have access to the same data, how can they draw different conclusions?

vazorg [7]

If a group of scientists have access to one data, from the data they can draw conclusions either through mathematics or just thought experiments.

Those thought experiments is different for any scientist, no one thinks the same especially when the topic is difficult.

For example when talking about parallel universes, scientists have come up with the weirdest examples of a multiverse. Some thinking of a brane universe, while others say that its a landscape universe, quilted universe. All of their 'evidence' seems correct but they have opposite meanings.

A weird analogy is 'religion'. All the religions seem to have 'evidences' (hardly) that attract people towards it, they all make sense but that doesn't mean that their evidence is right.

----

Now if they're trying to break down the data using maths, there could be a great uncertainty and measurement error that if done enough could change the whole idea behind the data.

Interesting question, I can babble for days for this but lets keep it as that

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3 years ago

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A car has a mass of 1600 kg. It is stuck in the snow and is being pulled out by a cable that applies a force of 7560 N due north

sergiy2304 [10]

Answer:

Acceleration of the car will be $a=0.1375m/sec^2$