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2 years ago

Which of the following describes what needs to occur to reduce force and to do the same amount of work?

1 answer:

5 0

Work is defined to be force multiplied by distance. If one component of the equation is decreased while aiming to keep the resulting value, then the other component must be increased. In that sense, to keep the same amount of work while reducing the force, the distance where the force is exerted should be increased.

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A 57 g ice cube can slide without friction up and down a 33 ∘ slope. The ice cube is pressed against a spring at the bottom of t

beks73 [17]

The springs stored energy is transferred to the cube as kinetic energy and then by the slop the KE is converted to height energy.

0.5 . k . x^2 = 0.5 . m . v^2 = m . g . ∆h 

0.5 . 50 . (0.1^2) = 0.05 . 9.8 . ∆h 

∆h = 0.51 m = 51 cm 

This is the height gained 
Distance along the slope = ∆h / sin 60 = 0.589 = 59 cm 

In the second case, the stored spring energy is converted into height energy AND frictional heat energy. 

The height energy is m . g . d sin 60 where d is the distance the cube moves along the slope. 

The Frictional energy converted is F . d 

F ( the frictional force ) = µ . N 

N ( the reaction to the component of the gravity force perpendicular to the surface of the slope ) = m . g . cos60 

Total energy converted 

0.5 . k . x^2 = (m . g . dsin60) + (µ . m . g . cos60 . d ) 

Solve for d 

d = 0.528 = 53 cm

5 0

2 years ago

Glycerin (C3H8O3) is a nonvolatile liquid. What is the vapor pressure of a solution made by adding 154 g of glycerin to 316 mL o

garri49 [273]

Answer:

$P_{sol}=50.4\ mm.Hg$

Explanation:

According to given:

molecular mass of glycerin, $M_g=3\times 12+8+3\times 16=92\ g.mol^{-1}$

molecular mass of water, $M_w=2+16=18\ g.mol^{-1}$

∵Density of water is $0.992\ g.cm^{-3}= 0.992\ g.mL^{-1}$

∴mass of water in 316 mL, $m_w=316\times 0.992=313.5 g$

mass of glycerin, $m_g=154\ g$

pressure of mixture, $P_x=55.32\ torr= 55.32\ mm.Hg$

temperature of mixture, $T_x=40^{\circ}C$

Upon the formation of solution the vapour pressure will be reduced since we have one component of solution as non-volatile.

moles of water in the given quantity:

$n_w=\frac{m_w}{M_w}$

$n_w=\frac{313.5}{18}$

$n_w=17.42 moles$

moles of glycerin in the given quantity:

$n_g=\frac{m_g}{M_g}$

$n_g=\frac{154}{92}$

$n_g=1.674 moles$

Now the mole fraction of water:

$X_w=\frac{n_w}{n_w+n_g}$

$X_w=\frac{17.42}{17.42+1.674}$

$X_w=0.912$

Since glycerin is non-volatile in nature so the vapor pressure of the resulting solution will be due to water only.

$\therefore P_{sol}=X_w\times P_x$

$\therefore P_{sol}=0.912\times 55.32$

$P_{sol}=50.4\ mm.Hg$

7 0

2 years ago

Wavelength is measured in hertz true or false?

g100num [7]

Wavelength is measured in various units of distance (mm, cm, m, etc.). Frequency uses hertz, but that is not what the question is asking. Therefore, the answer is false.

3 0

2 years ago

The main equation we are using to measure the e/m ratio is:

kow [346]

Answer:

Explanation:

the electrons beams deflection radius will be halved.

6 0

2 years ago

A radio-controlled car increases its kinetic energy from 4 j to 12 j over a distance of 2 m. what was the average net force on t

just olya [345]

The answer to this is easy once you look at the units for Joules. 1 Joule = 1 N.m (Newton.meter). The 'Newton' is the units of force that we are trying to find, and we know the meters is 2, from the question. So you have an 8Joule or 8N.m energy difference over 2 meters.

well if we know the meters, then the real question is written as:
8N.m = ?N x 2m
so just solve for N;
N = 8N.m / 2m = 4
So F = 4N

3 0

3 years ago