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3 years ago

A 110-pound person pulls herself up 4.0 feet. This took her 2.5 seconds. How much power was developed?

Physics

2 answers:

mrs_skeptik [129]3 years ago

5 0

Answer:

0.32 Hp is the answer. right

lesya [120]3 years ago

4 0

Answer: Power developed by her is <u><em>0.32 hp</em></u>

Explanation:

Work done , W= Force(F) X Displacement (d) in the direction of force

Thus work done , $W=Fd=110\times 4.0 ft-lbf = 440 ft-lbf$

Now 1.0 ft-lbf = 1.355 joules of energy

Therefore , work done, W= 440x 1.355 J = 596.2 J

Average Power , $P=\frac{work done(W)}{time (t)}$

=> $P=\frac{596.2}{2.5} watts = 238.5 watts$

We know 746 hp = 1.0 watts

=> $P=\frac{238.5}{746} hp=0.32 hp$

Thus average power developed by her is 0.32 hp

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Stolb23 [73]

Answer:

μ = mg/kx

Explanation:

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3 years ago

A car has a mass of 1.00 × 103 kilograms, and it has an acceleration of 4.5 meters/second2. What is the net force on the car?

aksik [14]

ANSWER

C. $F=4.5 \times10^3$ . newtons

EXPLANATION

According to Newton's second law,

$F_{net}=ma$ , where

$m=1.00\times 10^3kg$ is the mass measured in kilograms.

and

$a=4.5ms^{2}$ is the acceleration in metres per second square.

We substitute these values to obtain,

$F=1.00\times10^3 \times 4.5$ .

We rearrange to get,

$F=1.00\times4.5 \times10^3$ .

We multiply out the first two numbers and leave our answer in standard form to get,

$F=4.5 \times10^3 N$ .

The correct answer is C

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3 years ago

a vehicle travels at a constant speed of 65 mph for 4 hours how far has this vehicle travelled in this time

Nostrana [21]

260 miles.................

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3 years ago

PLEASE HELP!

Harman [31]

Hey user!

your answer is here..

correct option is A. steel

we know that sounds travel faster in solid as compared to gas and liquids. in gas the molecules are very loosely packed and there is lot of space between so it takes more time to pass sound from each other. and in liquid, the molecules are closer as compared to gas hence it will be little faster and in solid, the molecules are very tightly packed so it will be the fastest. and among these options, steel is the only solid so the speed of sound in steel will be the fastest.

and note that the closer the molecules are to each other ( tightly packed ) makes the bond also tighter and less time to pass sound.

cheers!!

8 0

3 years ago