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3 years ago

7

A man in a strength competition pulls an 18-wheel truck 3.10 m in 20.5 s. There is a cable that is attached to his body that exe

rts a horizontal force of 756 N. What is the power expended by the man?

1 answer:

larisa [96]3 years ago

4 0

Answer:

114.32195122 but Round your answer to three significant figures.) is 114

Explanation:

Just took the test

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The filament of a certain lamp has a resistance that increases linearly with temperature. When a constant voltage is switched on

Neporo4naja [7]

Answer:

162.8 K

Explanation:

initial current = io

final current, i = io/8

Let the potential difference is V.

coefficient of resistivity, α = 43 x 10^-3 /K

Let the resistance is R and the final resistance is Ro.

The resistance varies with temperature

R = Ro ( 1 + α ΔT)

V/i = V/io (1 + α ΔT )

8 = 1 + 43 x 10^-3 x ΔT

7 = 43 x 10^-3 x ΔT

ΔT = 162.8 K

Thus, the rise in temperature is 162.8 K.

5 0

3 years ago

Determine the projection (magnitude and sign), or component, of vector v1 along the direction of vector v2. Your answer could be

professor190 [17]

Answer:

- 1.07 ft

Explanation:

V1 = (-5, 7, 2)

V2 = (3, 1, 2)

Projection of v1 along v2, we use the following formula

=\frac{\overrightarrow{V1}.\overrightarrow{V2}}{V2}

So, the dot product of V1 and V2 is = - 5 (3) + 7 (1) + 2 (2) = -15 + 7 + 4 = -4

The magnitude of vector V2 is given by

= $\sqrt{3^{2}+1^{2}+2^{2}}=3.74$

So, the projection of V1 along V2 = - 4 / 3.74 = - 1.07 ft

Thus, the projection of V1 along V2 is - 1.07 ft.

so we need to find the direction of v2

7 0

4 years ago

Hunk travelled 540 km at an average speed of 90 km/h. If Tim completed the same amount of distance with 1 hour and 30 min less t

lina2011 [118]

Answer:120

Explanation:it just is trust me

8 0

3 years ago

An object is released from rest and falls a distance h during the first second of time. How far will it fall during the next sec

Viefleur [7K]

Answer:

E. 3h

Explanation:

We know that

u = 0 m/s.

velocity after t = 1s

v = u+gt = 0+9.81 x 1s= 9.81 m/s

distance covered in 1st sec

= =>> ut+0.5 x g x t²

=>>0 + 0.5x 9.81 x 1 = 4.90m

Let 4.90 be h

distance travelled in 2nd second will now be used

So velocity after t = 1s

=>>1 x t+ 0.5 x g x t²

=>9.81x 1 + 0.5 x 9.81 x 1 = 3 x 4.90

So since h= 4.90

Then the ans is 3x h = 3h

3 0

3 years ago

The formula v = √ 2.3 r models the maximum safe speed, v , in miles per hour, at which a car can travel on a curved road with ra

Archy [21]

Answer:

562 miles per hour.

Explanation:

As given in the question, the formula for the maximum speed on a curved road is

$v=\sqrt{2.3}$ $r$

Given value of $r=370$ feet

So the maximum safe speed will be

$v=\sqrt{2.3} \times 370 = 1.52\times 370 = 562.4$ miles per hour.

Rounding off to the nearest whole number we get the maximum safe speed at the curved road is 562 miles per hour.

6 0

4 years ago