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3 years ago

How do heat insulators work

Physics

2 answers:

adelina 88 [10]3 years ago

5 0

How they work is that they help keep the heat in and cool air out.

a_sh-v [17]3 years ago

4 0

The heat is transferred to one material to another, however insulators minimize that transfer, keeping it in the area, warming it.

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An electric motor with a 1200 hp output drives a machine with an efficiency of 60%. What is the energy output of the machine per

kirill [66]

Answer:

536,904 J/s

Explanation:

The energy output from motor is the input energy in the machine.

We know that efficiency is percentage energy ouput to energy input, and expressed as

$n=\frac {E_o}{E_i}$

Where n and E represent efficiency and energy respectively, subscripts o and i represent output and input respectively. Since for the machine we have the input energy then the output will be the product of efficiency and input energy

Energy output=0.6*1200 hp=720 hp

Converting hp to J/s we multiply by 745.7

Energy is 720*745.7=536,904 J/s

4 0

3 years ago

A boy whirls a stone in a horizontal circle of radius 1.4 m and at height 1.5 m above ground level. The string breaks, and the s

balandron [24]

Answer: $233.23 m/s^2$

Explanation:

Given

radius of circle=1.4 m

Height of stone above ground=1.5 m

Horizontal distance(R)=10 m

It is given at the time of break stone flies horizontally thus stone to cover a height of 1.5 m in time t before reaching ground

$1.5=0+\frac{gt^2}{2}$

t=0.55 s

Initial horizontal velocity at the time of break is given by u

$R=u\times t$

$10=u\times 0.55$

u=18.07 m/s

Therefore magnitude of centripetal acceleration is given by

$a_c=\frac{u^2}{r}=\frac{18.07^2}{1.4}=233.23 m/s^2$

6 0

3 years ago

After you pick up a spare, your bowling ball rolls without slipping back toward the ball rack with a linear speed of 2.85 m/s. T

motikmotik

Answer:

V' = 0.84 m/s

Explanation:

given,

Linear speed of the ball, v = 2.85 m/s

rise of the ball, h = 0.53 m

Linear speed of the ball, v' = ?

rotation kinetic energy of the ball

$KE_r = \dfrac{1}{2}I\omega^2$

I of the moment of inertia of the sphere

$I = \dfrac{2}{5}MR^2$

v = R ω

using conservation of energy

$KE_r = \dfrac{1}{2}( \dfrac{2}{5}MR^2)(\dfrac{V}{R})2$

$KE_r = \dfrac{1}{5}MV^2$

Applying conservation of energy

Initial Linear KE + Initial roational KE = Final Linear KE + Final roational KE + Potential energy

$\dfrac{1}{2}MV^2 + \dfrac{1}{5}MV^2 = \dfrac{1}{2}MV'^2 + \dfrac{1}{5}MV'^2 + M g h$

$0.7 V^2 = 0.7 V'^2 + gh$

$0.7\times 2.85^2 = 0.7\times V'^2 +9.8\times 0.53$

V'² = 0.7025

V' = 0.84 m/s

the linear speed of the ball at the top of ramp is equal to 0.84 m/s

6 0

3 years ago

Branches of sicence

Sonja [21]

Answer:

physical science

earth science and life science

5 0

3 years ago

Read 2 more answers

If two solutions have unequal concentrations of a solute, the solution with the lower concentration is called

marta [7]

Obviouskly lower concentrstion

6 0

3 years ago