All categories

3 years ago

To obtain the same resistance force, a greater force must be exerted in a machine of lower efficiency than in a machine

Physics

1 answer:

Sindrei [870]3 years ago

7 0

Answer: True.

Explanation:

A resistance force is also known as friction. And the efficiency of a machine is affected by friction.

A machine of lower efficiency has higher magnitude of friction than a machine of higher efficiency.

Therefore, To obtain the same resistance force, a greater force must be exerted in a machine of lower efficiency than in a machine of higher efficiency. This is true

You might be interested in

Why is it important to have a closed circuit?

yaroslaw [1]

D. It allows the flow of an electric current in the circuit.

<h3>Why is it important to have a closed circuit?</h3>

Closed circuit allows the flow of current in the circuit from the battery to the bulb. If the circuit is open then the current will not reach to the bulb or other appliances.

So we can conclude that It is important to have a closed circuit because it allows the flow of an electric current in the circuit.

Learn more about circuit here: brainly.com/question/2969220

#SPJ1

7 0

1 year ago

A perturbation in the temperature of a stream leaving a chemical reactor follows a decaying sinusoidal variation, according to t

Vsevolod [243]

Derivating the function of the temperature and equating to 0, we can find the critical points:

$T'(t)=-a\cdot5e^{-at}\cdot\sin(wt)+w\cos(wt)\cdot5e^{-at}\\\\ 0=5e^{-at}(-a\sin(wt)+w\cos(wt))$

As $5e^{-at}\neq0$ :

$0=-a\sin(wt)+w\cos(wt)\iff a\sin(wt)=w\cos(wt)\iff \\\\\sin(wt)=\dfrac{w}{a}\cos(wt)\iff \tan(wt)=\dfrac{w}{a}\iff wt=\tan^{-1}\left(\dfrac{w}{a}\right)\iff \\\\\boxed{t=\dfrac{1}{w}\tan^{-1}\left(\dfrac{w}{a}\right)}$

Replacing:

$T(t)=5e^{-at}\cdot\sin(wt)=5e^{-\frac{a}{w}\tan^{-1}\left(\frac{w}{a}\right)}\cdot\sin(\tan^{-1}\left(\dfrac{w}{a}\right))$

We can reach: $\sin(\tan^{-1}\left(\dfrac{w}{a}\right))=\dfrac{w}{\sqrt{w^2+a^2}}$

Hence:

$T(t)=\dfrac{5w}{\sqrt{w^2+a^2}}e^{-\frac{a}{w}\tan^{-1}\left(\frac{w}{a}\right)}$

4 0

2 years ago

Ocean waves that measure 12m from crest to adjacent crest pass by a fixed point every 2.0s what is the speed of the waves

Darina [25.2K]

Because there is a 1.2m distance between the crest and the adjacent trough in the series.

7 0

3 years ago

a student holds a 3.0kg mass in each hand while sitting on a rotating stool. when his arms are extended horizontally, the masses

sweet-ann [11.9K]

Answer:

Explanation:

Due to change in the position of 3 kg mass , the moment of inertia of the system changes , due to which angular speed changes . We shall apply conservation of angular momentum , because no external torque is acting .

Initial moment of inertia I₁ = M R² = 3 x 1 ² = 3 kg m²

Final moment of inertia I₂ = M R² = 3 x .3 ² = 0.27 kg m²

Applying law of conservation of angular momentum

I₁ ω₁ = I₂ ω₂

Putting the values ,

3 x .75 = .27 x ω₂

ω₂ = 8.33 rad / s

New angular speed = 8.33 rad /s .

8 0

2 years ago

A wheel turns through 5.5 revolutions while being accelerated from rest at 20rpm/s.(a) What is the final angular speed ? (b) How

alina1380 [7]

Answer:

(a) The final angular speed is 12.05 rad/s

(b) The time taken to turn 5.5 revolutions is 5.74 s

Explanation:

Given;

number of revolutions, θ = 5.5 revolutions

acceleration of the wheel, α = 20 rpm/s

number of revolutions in radian is given as;

θ = 5.5 x 2π = 34.562 rad

angular acceleration in rad/s² is given as;

$\alpha = \frac{20 \ rev}{min} *\frac{1}{s} *(\frac{2\pi \ rad}{1 \ rev } *\frac{1 \ min}{60 \ s}) \\\\\alpha = 2.1 \ rad/s^2$

(a)

The final angular speed is given as;

$\omega _f^2 = \omega_i ^2 + 2\alpha \theta\\\\\omega _f^2 = 0 + 2\alpha \theta\\\\\omega _f^2 = 2\alpha \theta\\\\\omega _f = \sqrt{2\alpha \theta}\\\\ \omega _f = \sqrt{2(2.1) (34.562)}\\\\ \omega _f = 12.05 \ rad/s$

(b) the time taken to turn 5.5 revolutions is given as

$\omega _f = \omega _i + \alpha t\\\\12.05 = 0 + 2.1t\\\\t = \frac{12.05}{2.1} \\\\t = 5.74 \ s$

3 0

2 years ago