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3 years ago

Select the correct answer.

Physics

2 answers:

FinnZ [79.3K]3 years ago

8 0

2 hours is the answer because you do 45x2=90

Bumek [7]3 years ago

3 0

Answer:

B. 2 Hours

Explanation:

If you are going 45 miles per hour, you will travel 45 miles in 1 hour. It will take you 2 hours to travel 90 miles at a speed of 45 miles per hour.

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What unit is used for speed? 1. m/s 2. S 3. m/s2 4. m

bixtya [17]

Answer:

The unit of speed is m/s.

7 0

3 years ago

If you are six feet tall how far back from a 3 foot mirror do you have to stand in order to see yourself completely?

OverLord2011 [107]

Answer:

you would have to stand 6 ft back

Explanation:

7 0

3 years ago

You are given a vector in the xy plane that has a magnitude of 90.0 units and a y component of -61.0 units. A) Assuming the x co

kvasek [131]

Answer:

A) magnitude = sqrrt(147.1^2 + 61^2) = 159.2 units

B)22.5° (clockwise form -ve X axis)

Explanation:

given vector = V1 = x i - 60 j

magnitude of V1 = 90

x - component can be found out by resultant formula

90^2 = x^2 + (-60)^2

x = 67.08 = 67.1 units (3sf)

FOR THE VECTOR 80 UNITS IN -VE X DIRECTION

The X component is -80-------(1)

The Y component is 0 ---------(2)

For the x- component of new added vector:

(1)----------- x + 67.1 = -80

x = -147.1 = -147.1

For the y- component of new added vector:

(2)---------- y - 61 = 0

y = 61.0 (3sf)

the new added vector is = -147.1 i + 61 j

magnitude = sqrrt(147.1^2 + 61^2) = 159.2 units

direction = arctan (61 / 147.1)

= 22.5° (clockwise form -ve X axis)

4 0

3 years ago

One uniform ladder of mass 30 kg and 10 m long rests against a frictionless vertical wall and makes an angle of 60o with the flo

yuradex [85]

Answer:

μ = 0.37

Explanation:

For this exercise we must use the translational and rotational equilibrium equations.

We set our reference system at the highest point of the ladder where it touches the vertical wall. We assume that counterclockwise rotation is positive

let's write the rotational equilibrium

W₁ x/2 + W₂ x₂ - fr y = 0

where W₁ is the weight of the mass ladder m₁ = 30kg, W₂ is the weight of the man 700 N, let's use trigonometry to find the distances

cos 60 = x / L

where L is the length of the ladder

x = L cos 60

sin 60 = y / L

y = L sin60

the horizontal distance of man is

cos 60 = x2 / 7.0

x2 = 7 cos 60

we substitute

m₁ g L cos 60/2 + W₂ 7 cos 60 - fr L sin60 = 0

fr = (m1 g L cos 60/2 + W2 7 cos 60) / L sin 60

let's calculate

fr = (30 9.8 10 cos 60 2 + 700 7 cos 60) / (10 sin 60)

fr = (735 + 2450) / 8.66

fr = 367.78 N

the friction force has the expression

fr = μ N

write the translational equilibrium equation

N - W₁ -W₂ = 0

N = m₁ g + W₂

N = 30 9.8 + 700

N = 994 N

we clear the friction force from the eucacion

μ = fr / N

μ = 367.78 / 994

μ = 0.37

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3 years ago

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djyliett [7]

Answer:

dear can you provide the circuit of the robot

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3 years ago