Which device uses electricity to produce a rotational motion? A computer C magnet B generator D motor

A professor's office door is 0.91 m wide, 2.0 m high, and 4.0 cm thick; has a mass of 25 kg; and pivots on frictionless hinges.

olasank [31]

Answer:

F= 5.71 N

Explanation:

width of door= 0.91 m

door closer torque on door= 5.2 Nm

In order to hold the door in open position we need to exert an equal and opposite torque, to the door closer torque, on the door.

so wee need to exert 5.2 Nm torque on the door.

If we want to apply minimum force to exert the required torque we need to apply force perpendicularly on the door knob (end of door) so that to to greater moment arm.

T= r x F

T= r F sin∅

F= T/ (r * sin∅)

F= 5.2/ (0.91 * 1)

F= 5.71 N

5 0

3 years ago

A space station has a large ring-like component that rotates to simulategravity for the crew. This ring has a massM= 2.1×105kg a

ivann1987 [24]

Answer:

Each thruster has to applied a force of 294.5N in tangential direction

Explanation:

Mass of the ring ,M =2.1×105kg

Mass of the ship ,m = 3.5×104kg

Radius of the ring R = 86.0 m

distance of ship from center of the ring, r =31.0 m

Let force applied by each thruster be F

Time taken to reach gravity ,t = 3hrs = 3600× 3 =10800sec

The movement of ring make the object kept at the edge feel a force of centrifuge in outward direction.

Centrifugal force = weight of the object on earth

Assume the ring is moving with angular speed ω

Centripetalforce of the object kept at ring

m₁R ω²=m₁g (m₁=mas of object)

⇒Rω² = g

⇒ω = √g/R

The ring start from 0 angular speed with constant angular acceleration

Let the constant angular acceleration be ∝

∝ = ω / t

(ω = √g/R)

∝ = $\frac{1}{t } \sqrt{\frac{g}{R} } }$

Consider Torque on the ring and ship system

T = FR + FR = 2FR

Moment of inertia of ring ship system

I = I(ring)+I(ship)+I(ship)

= MR² + mr² + mr² = MR² + 2mr²

angular acceleration of the ring ship system

∝ = $\frac{2FR}{MR^2 + 2mr^2}$

Now we have ,

∝ = $\frac{1}{t} \sqrt{\frac{g}{R} }$ , ∝ = $\frac{2FR}{MR^2+2mr^2}$

equating both values

We have,

$F = \frac{MR^2+2mr^2}{2Rt} \sqrt{\frac{g}{R} }$

where,

m = 2.1 × 10⁵kg, R = 86m, m = 3.5 × 10₄kg,

r = 31m, g = 9.8m/s² , t = 10800sec

$F = \frac{(2.1 \times 10^5 \times86^2)+(2\times3.5v10^4\times31^2) }{2\times86\times10800} \times\sqrt{\frac{9.8}{86} } \\\\F = 294.47N\\\approx294.5N$

Each thruster has to applied a force of 294.5N in tangential direction

3 0

3 years ago

Helppppp pleaseeeee!!!!!!!

Lorico [155]

The first one is Water
The second one is Juice
The third one Vinegar
The fourth one is Milk
The last one may be Shampoo

3 0

3 years ago

Read 2 more answers

Questions 15 out of 20

Olin [163]

Answer:

D

Explanation:

7 0

3 years ago

Match the following:

Nadusha1986 [10]

Answer:

Statement 1 can be matched with option f (Van der waal forces)

Statement 2 can be matched with option b (Liquid crystal)

statement 3 can be matched with option e (Thermal expansion)

Statement 4 can be matched with option g (Viscosity)

Statement 5 can be matched with option b (Fractional distillation)

Statement 6 can be matched with option a (Diffusion)

Statement 7 can be matched with option d (Miscible)

Explanation:

Van der waal forces are weak inter-molecular bonds found between covalent molecules e.g molecules of graphite, noble gases etc
Liquid crystals are substances that behave like liquids and its molecules orientate itself like a crystal (solid). They can be referred to as LCs.
Thermal expansion is a phenomenon where by matter changes in shape, volume and area due to a change in temperature.
Viscosity is a term used to describe a fluid's resistance to flow. It is also used to describe the internal friction that a moving liquid experiences. Oil is more viscose than liquid water
Fractional distillation is a separation technique used in separating two or more miscible liquids of close boiling points. For example petrol and diesel oil can be separated using fractional distillation. An industrial application of this technique is Fractional distillation of crude oil where crude oil is separated into its components
Diffusion is the movement of dissolved particles, gases, liquid from a region of higher concentration to a region of lower concentration until there is a equal balance. This can occur when you spray a perfume in one end of a room. You will get to smell the perfume at the other end after some time. Diffusion is fastest in gas as compared to liquids and solids.
Miscible is a word used to describe liquids forming a homogeneous mixture when dissolved in each other. Miscibility is factor to be considered when separating mixture.

7 0

3 years ago

Which device uses electricity to produce a rotational motion? A computer C magnet B generator D motor​

Which device uses electricity to produce a rotational motion? A computer C magnet B generator D motor