Which statement illustrates how engineering has influenced society?

What is the average force (average with respect to height of the barbell from the ground) exerted by the weightlifter in the pro

Novay_Z [31]

This question is incomplete, the complete question is;

A weightlifter holds a 1,300 N barbell 1 meter above the ground. One end of a 2-meter-long chain hangs from the center of the barbell. The chain has a total weight of 400 N. How much work (in J) is required to lift the barbell to a height of 2 m?

What is the average force (average with respect to height of the barbell from the ground) exerted by the weightlifter in the process?

Answer: Average force exerted by the weightlifter in the process = 1600N

Explanation:

To find Work done to lift a barbell and half of the hanging chain we say;

W₁ = ( 1300N + (1/2 × 400N)) × 1m

W₁ = (1300 + 200) Nm

W₁ = 1500J

now work done to lift the upper half of the chain we say:

W₂ = (1/2 × 400N) × (1/2 × 1m)

W₂ = 200N × 0.5m

W₂ = 100J

So total work done will be

W = W₁ + W₂

W = 1500J + 100J

W = 1600J

To find the average force exerted by the weight lifter, we say;

F = W/D

F = (1600 / 1m) N

F = 1600N

∴Average force = 1600N

6 0

3 years ago

PLEASE HELP!!!!!!

prohojiy [21]

Answer:

I don't know i am sry............

5 0

3 years ago

Read 2 more answers

A car moving round a circular racing track takes 120s to do a lap of 8km what is the speed in km/hr.

Harlamova29_29 [7]

Answer:

Solution in photo

Explanation:

7 0

3 years ago

A janitor standing on the top floor of a building wishes to determine the depth of the elevator shaft. They drop a rock from res

Bumek [7]

Answer:

Part a)

H = 26.8 m

Part b)

error = 7.18 %

Explanation:

Part a)

As the stone is dropped from height H then time taken by it to hit the floor is given as

$t_1 = \sqrt{\frac{2H}{g}}$

now the sound will come back to the observer in the time

$t_2 = \frac{H}{v}$

so we will have

$t_1 + t_2 = 2.42$

$\sqrt{\frac{2H}{g}} + \frac{H}{v} = 2.42$

so we have

$\sqrt{\frac{2H}{9.81}} + \frac{H}{336} = 2.42$

solve above equation for H

$H = 26.8 m$

Part b)

If sound reflection part is ignored then in that case

$H = \frac{1}{2}gt^2$

$H = \frac{1}{2}(9.81)(2.42^2)$

$H = 28.7 m$

so here percentage error in height calculation is given as

$percentage = \frac{28.7 - 26.8}{26.8} \times 100$

$percentage = 7.18$

5 0

3 years ago

What do you need to verify in a patient's profile? A. Name, history of illness, medication, dose, strength, frequency B. Name, a

Lubov Fominskaja [6]

Hey there friend :)

I would go with Choice A

Sorry if wrong :(

Have a Fabulous day!

3 0

4 years ago

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