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3 years ago

Why are all machines not 100% efficient A. Mass B. Gravity C. Friction D. Distance

Physics

2 answers:

Anon25 [30]3 years ago

7 0

All machines are not 100% efficient because of <span>C. Friction</span>

Monica [59]3 years ago

4 0

C. Friction is the correct answer

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;-; please help me....

sineoko [7]

The answer is 24N. Since the body is moving with constant velocity all the forces must balance (equal & opposite)

5 0

3 years ago

How long does it take a car traveling at 50 mph to travel 75 miles? Use one of the following to find the answer.

yanalaym [24]

Answer:

90 Minutes

Explanation:

t = d / v

t = 75 / 50

t = 1.5 hour

t = 90 minutes.

8 0

2 years ago

The force exerted by the wind on the sails of a sailboat is Fsail = 330 N north. The water exerts a force of Fkeel = 210 N east.

Elena L [17]

Answer:

The magnitude of the acceleration is $a_r = 1.50 \ m/s^2$

The direction is $\theta = 32.5 6^o$ north of east

Explanation:

From the question we are told that

The force exerted by the wind is $F_{sail} = (330 ) \ N \ north$

The force exerted by water is $F_{keel} = (210 ) \ N \ east$

The mass of the boat(+ crew) is $m_b = 260 \ kg$

Now Force is mathematically represented as

$F = ma$

Now the acceleration towards the north is mathematically represented as

$a_n = \frac{F_{sail}}{m_b}$

substituting values

$a_n = \frac{330 }{260}$

$a_n = 1.269 \ m/s^2$

Now the acceleration towards the east is mathematically represented as

$a_e = \frac{F_{keel}}{m_b }$

substituting values

$a_e = \frac{210}{260}$

$a_e =0.808 \ m/s^2$

The resultant acceleration is

$a_r = \sqrt{a_e^2 + a_n^2}$

substituting values

$a_r = \sqrt{(0.808)^2 + (1.269)^2}$

$a_r = 1.50 \ m/s^2$

The direction with reference from the north is evaluated as

Apply SOHCAHTOA

$tan \theta = \frac{a_e}{a_n}$

$\theta = tan ^{-1} [\frac{a_e}{a_n } ]$

substituting values

$\theta = tan ^{-1} [\frac{0.808}{1.269 } ]$

$\theta = tan ^{-1} [0.636 ]$

$\theta = 32.5 6^o$

5 0

3 years ago

A train accelerates to a velocity of 500 m/s over time of 2s. The acceleration it experienced was 50m/s2. What was its initial v

ValentinkaMS [17]

Explanation:

We know ,

v = u + at
u = v - at
u = 500 - 2*50
u = 400 m/s

7 0

3 years ago

A car travelling at 5.0 m/s starts to speed up. After 3.0 s its velocity has increased to 11 m/s. a) What is its acceleration? (

lions [1.4K]

initially, the car is traveling at 5.0 m/s.

so, we know acceleration for changing velocity is :

a = (v-v $_{o}$ )/t ..........(i)

where v is the final velocity

v $_{o}$ is the initial velocity

t is the time taken to change velocity

Now, as per the question :

initial velocity, v $_{o}$ =5.0 m/s

final velocity, v =11 m/s

time taken, t = 3 s

putting the values in equation (i),

a = ( 11-5 )/3

a = 2 m/s²

Therefore, a, after 3 s, is <em>2 m/s².</em>

4 0

1 year ago