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7nadin3 [17]
3 years ago
15

A construction worker puts 20J of energy in to one strike of his hammer on the head of a nail. The energy transferred to driving

d nail in to d wood is 8J. What is d efficiency of d construction worker's hammering?​
Physics
2 answers:
KengaRu [80]3 years ago
4 0

Answer:

The efficiency can be found using the formula ;

efficiency=energy output divided by energy input ×100%.

efficiency=8.0j÷ 20j × 100%

efficiency=0.4 ×100%

efficiency=40%.

the efficiency of the hammer strike was 40%. vibration and heating of the nail are two possible reasons for the energy loss.

Slav-nsk [51]3 years ago
3 0

Answer:

efficiancy=40 percent

Explanation:

efficiency=energy output/energy input×100

efficiancy=8J/20J×100

efficiancy=0.4×100

efficiancy=40 percent

Mark brianliest if my answer suit your question..

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Butoxors [25]

Answer:

4. The equilibrium will shift to favor formation of NO2(g)

Explanation:

According to La Chatalier's Principle which states that when an equilibrium system undergoes changes either in temperature, volume or concentration; there will be in a change in the system in order to reach equilibrium.

From the above equation,

N2O4(g) ⇀↽ 2 NO2(g)

From the above reaction, there are 2 moles of gaseous product on the left and 1 mole of gaseous reactant.

Therefore, there are more moles of gases in the left hand side than the right hand side.

Because a decrease in volume favors the direction that produces fewer moles, an increase in volume will therefore shift this system towards the side with more moles of gases that is, more products are formed hence, this system will shift to right and produce more moles of products i.e more NO2(g) formed.

6 0
2 years ago
15) On a cold day, you take in 4.2 L (i.e., 4.2 x 10-3 m3) of air into your lungs at a temperature of 0°C. If you hold your brea
Rudiy27

Answer:

4.8L ( i.e 4.8 x 10^-3 m3)

Explanation:

Step 1:

Data obtained from the question.

Initial volume (V1) = 4.2L

Initial temperature (T1) = 0°C

Final temperature (T2) = 37°C

Final volume (V2) =?

Step 2:

Conversion of celsius temperature to Kelvin temperature. This is illustrated below

K = °C + 273

T1 = 0°C = 0°C + 273 = 273K

T2 = 37°C = 37°C + 273 = 310K

Step 3:

Determination of the final volume.

Since the pressure is constant,

Charles' Law equation will be applied as shown below:

V1 /T1 = V2/T2

4.2/273 = V2 /310

Cross multiply to express in linear form

273 x V2 = 4.2 x 310

Divide both side by 273

V2 = (4.2 x 310)/273

V2 = 4.8L ( i.e 4.8 x 10^-3 m3)

Therefore, the volume of the air in the lungs at that point is 4.8L ( i.e 4.8 x 10^-3 m3)

3 0
3 years ago
A sheet of metal is 2mm wide 10cm tall and 15cm long. it was 4g. what is the density? <br>​
Hoochie [10]

Answer:

Ro = 133 [kg/m³]

Explanation:

In order to solve this problem, we must apply the definition of density, which is defined as the relationship between mass and volume.

Ro = m/V

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m = mass [kg]

V = volume [m³]

We will convert the units of length to meters and the mass to kilograms.

L = 15 [cm] = 0.15 [m]

t = 2 [mm] = 0.002 [m]

w = 10 [cm] = 0.1 [m]

Now we can find the volume.

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Ro = 0.004/0.00003\\Ro = 133 [kg/m^{3}]

3 0
2 years ago
If a reaction is exothermic, then which of the following statements is always true? If a reaction is exothermic, then which of t
sesenic [268]

Explanation:

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7 0
3 years ago
When numbers are very small or very large, it is convenient to either express the value in scientific notation and/or by using a
Oxana [17]

Answer:

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we have:

m = 0.005 g

To rewrite it in scientific notation, we must count by how many digits we have to move the dot on the right - in this case three. So in scientific notation is

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x=\frac{(1000 mg)(0.005 g)}{1 g}=5 mg

4 0
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