Nothing is exempt from ________, which states the total energy remains constant during a physical change.

The 80.0-lb boy at a is suspended from the cable that passes over the quarter circular cliff rock. determine if it is possible f

IrinaVladis [17]

<span>Yes, it's possible to hoist the child up. Let's first determine the maximum amount of pull that the woman can exert. That will be the simple product of her weight and the coefficient of static friction with her shoes and the ground. So 0.8 * 190 = 152. So far, so good, since 152 is greater than the boy's 80 lbs. But the cable rubs at the cliff edge and that means that the lady has to pull harder. Let's see how much harder. There will be 80 lbs of tension on the cable, pressing against the cliff edge. So let's multiply by the coefficient of friction to get how much that is 0.2 * 80 = 16 So friction will take 16 lbs of effort to overcome. So the lady needs to pull with 80 + 16 = 96 lbs of force to move the boy. And since we've determined earlier that she can pull with up to 152 lbs of force, she can easily hoist the child up.</span>

4 0

3 years ago

If the hiker starts climbing at an elevation of 350 ft, what will their change in gravitational potential energy be, in joules,

Kitty [74]

Answer:

352,088.37888Joules

Explanation:

Complete question;

A hiker of mass 53 kg is going to climb a mountain with elevation 2,574 ft.

A) If the hiker starts climbing at an elevation of 350 ft., what will their change in gravitational potential energy be, in joules, once they reach the top? (Assume the zero of gravitational potential is at sea level)

Chane in potential energy is expressed as;

ΔGPH = mgΔH

m is the mass of the hiker

g is the acceleration due to gravity;

ΔH is the change in height

Given

m = 53kg

g = 9.8m/s²

ΔH = 2574-350 = 2224ft

since 1ft = 0.3048m

2224ft = (2224*0.3048)m = 677.8752m

Required

Gravitational potential energy

Substitute the values into the formula;

ΔGPH = mgΔH

ΔGPH = 53(9.8)(677.8752)

ΔGPH = 352,088.37888Joules

Hence the gravitational potential energy is 352,088.37888Joules

7 0

3 years ago

Which change will cause an increase in the electric current produced through electromagnetic induction?using more wire loops in

allsm [11]

<span>using more wire loops in the solenoid</span>

4 0

3 years ago

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Definition These are the components of the reservoirs of oxygen that are exchanged in our environment.

andrew11 [14]

Answer:

Oxygen cycle

Explanation:

The components of the reservoirs of oxygen that are exchange in our environment is the oxygen cycle

It suggests the movement of oxygen between the living and non-living parts.

The cycle does not account for oxygen that is trapped and cannot be exchanged in nature.
Oxygen is important component of the atmosphere.
Gaseous exchange between living organisms and atmosphere involves oxygen to a very large extent.

4 0

3 years ago

If the current in a wire increases from 5 A to 10 A, what happens to its magnetic field? If the distance of a charged particle f

dsp73

1. The magnitude of the magnetic field doubles

Explanation: the intensity of the magnetic field produced by a current-carrying wire is given by:

$I=\frac{\mu_0 I}{2 \pi r}$

where $\mu_0$ is the vacuum permeability, I is the current in the wire, r is the distance from the wire.

As we see from the formula, the intensity of the magnetic field is directly proportional to the current: if the current increases from 5 A to 10 A, it means it doubles, so the magnetic field doubles as well.

2. The magnitude of the magnetic field halves

Explanation: the intensity of the magnetic field produced by a current-carrying wire is given by:

$I=\frac{\mu_0 I}{2 \pi r}$

We see that the magnitude of the magnetic field is inversely proportional to the distance from the wire (r). In this case, the distance of the particle is changed from 10 cm to 20 cm, so it is doubled: therefore, the magnitude of the field will become half of the initial value.

3. The force reverses direction

Explanation: the force exerted on a charged particle in a magnetic field is:

$F=qvB sin \theta$

where q is the charge, v is the speed of the particle, B is the magnetic field intensity and $\theta$ the angle between the direction of v and B. If the charge of the particle is switched from 2 µC to –2µC, the magnitude of the force does not change (because the absolute value of q does not change), however the charge q gets a negative sign (-), so the sign of the force changes and gets a negative sign too, so the force reverses direction.

7 0

3 years ago

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