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3 years ago

8

To pull a nail out of a wood board a carpenter does 1000 J of work. The hammer he uses does 835 J of work. What is the efficienc

y of the hammer?

1 answer:

saw5 [17]3 years ago

7 0

Answer:

83.5%

Explanation:

You might be interested in

The step-down transformer gives a current of 10A at 24v if the primary voltage is 240v calculate the

Zepler [3.9K]

You probably do this as a DC circuit which is not quite correct, but it will get you an answer. The study is a great deal more complicated.

Problem One: Secondary Power.

W = E * I

E = 10 A

I = 24V

W = 24 * 10

W = 240 Watts.

Here's the thing you have to know. These transformers are 100% efficient (or are assumed so). So whatever wattage is in the secondary, it is the same as that in the primary.

Primary Power = Secondary Power

Secondary Power = 240 Watts

Primary Power = 240 Watts

W = E * I

E = 240 volts

W = 240 watts

I = W/E = 240 / 240

I = 1 Amp. Answer Part One

Part Two

Answered above. 240 watts.

Part Three

Answered above. 240 watts.

Secondar

7 0

3 years ago

A 2.1 kg steel ball strikes a massive wall at 13.2 m/s at an angle of 64.8 ◦ with the perpendicular to the plane of the wall. It

solong [7]

Answer:

112 N

Explanation:

going through the question you would notice that some detail is missing, using search engines u was able to find a similar question on "https://socratic.org/questions/a-2-3-kg-steel-ball-strikes-a-wall-with-a-speed-of-8-5-m-s-at-an-angle-of-64-wit"

and here is the question i found

"A 2.3 kg steel ball strikes a wall with a speed of 8.5 m/s at an angle of 64⁰ with the surface. It bounces off with the same speed and angle. If the ball is in contact with the wall for 0.448 s. What is the average force exerted by the ball?"

you would notice that there is a change in the values from the question posted, hence we would only take the following part to complete our question, " If the ball is in contact with the wall for 0.448 s what is the average force exerted by the ball?" while retaining all original detail.

solution

mass of ball (m) = 2.1 kg

speed of ball (v) = 13.2 m/s

angle of contact (p) = 64.8°

time of contact (t) = 0.448 s

What is the average force exerted by the ball?

The average force exerted by the ball = $\frac{change in momentum}{change in time}$

where

The momentum changes only the direction perpendicular to the wall, hence the component of momentum perpendicular to the wall = m x v x sin (p) = 2.1 x 13.2 x sin 64.8 = 25.1 kg.m/s

since the ball strikes the wall and bounces off it with the same speed

and at the same angle, the component of momentum acting

perpendicular to the wall remains the same while hitting and leaving

the wall but in opposite directions.

Hence the component of momentum acting perpendicular to the wall while hitting and leaving the wall will be 25.1 kg.m/s and -25.1 kg.m/s respectively.

change in momentum = 25.1 - (-25.1) = 25.1 + 25.1 = 50.2 kg.m/s

change in time = 0.448 s

now substituting the above into the equation we have

The average force exerted by the ball = $\frac{50.2}{0.448}$ = 112 N

6 0

4 years ago

Which best explains how an object at rest deep in space and far from any massive body behaves compared to an object in free fall

7nadin3 [17]

Answer: They behave the same because, according to the principle of equivalence, the laws of physics work the same in all frames of reference.

Explanation:

According to the equivalence principle postulated by Einstein's Theory of General Relativity, acceleration in space and gravity on Earth have the same effects on objects.

To understand it better, regarding to the equivalence principle, Einstein formulated the following:

A gravitational force and an acceleration in the opposite direction are equivalent, both have indistinguishable effects. Because the laws of physics must be accomplished in all frames of reference.

Hence, according to general relativity, gravitational force and acceleration in the opposite direction (an object in free fall, for example) have the same effect. This makes sense if we deal with gravity not as a mysterious atractive force but as a geometric effect of matter on spacetime that causes its deformation.

3 0

3 years ago

Jupiter is 5.2 times farther from the sun than Earth is. Find Jupiter’s orbital period in Earth years

anzhelika [568]

You can solve this using Kepler's 3rd law. T is proportional to r^1.5. T(J) = T(E)*5.2^1.5 = 11.86 years.
<span>You can also solve it the hard way: Find M (sun's mass) and r(Jupiter's orbital radius) in m. Then use Kepler's equation T = 2pi*r^1.5/sqrt(GM).</span>

8 0

4 years ago

Chalk is an ionic compound. Which is a property of all ionic compounds that makes chalk particularly useful for writing on a cha

mario62 [17]

Answer:

the answer is B hardness and brittleness

Explanation:

I did edgenuity test ;)

7 0

3 years ago

Read 2 more answers