calculate the work done to stretch an elastic string by 40cm if a force of 10N produces an extension of 4cm in it?

A carnot engine operates between two heat reservoirs at temperatures th and tc. an inventor proposes to increase the efficiency

Sonja [21]

The efficiency of the first Carnot engine is
n1 = 1 - Th/T
The efficiency of the second Carnot engine is
n2 = 1 - T/Tc
The total efficiency of the engines put in series is
n = 1 - Th/Tc
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5 0

1 year ago

A satellite revolves around a planet at an altitude equal to the radius of the planet. the force of gravitational interaction be

USPshnik [31]

<span>f2 = f0/4 The gravity from the planet can be modeled as a point source at the center of the planet with all of the planet's mass concentrated at that point. So the initial condition for f0 has the satellite at a distance of 2r, where r equals the planet's radius. The expression for the force of gravity is F = G*m1*m2/r^2 where F = Force G = Gravitational constant m1,m2 = masses involved r = distance between center of masses. Now for f2, the satellite has an altitude of 3r and when you add in the planet's radius, the distance from the center of the planet is now 4r. When you compare that to the original distance of 2r, that will show you that the satellite is now twice as far from the center of the planet as it was when it started. So let's compare the gravitational attraction, before and after. f0 = G*m1*m2/r^2 f2 = G*m1*m2/(2r)^2 f2/f0 = (G*m1*m2/(2r)^2) / (G*m1*m2/r^2) The Gm m1, and m2 terms cancel, so f2/f0 = (1/(2r)^2) / (1/r^2) f2/f0 = (1/4r^2) / (1/r^2) And the r^2 terms cancel, so f2/f0 = (1/4) / (1/1) f2/f0 = (1/4) / 1 f2/f0 = 1/4 f2 = f0*1/4 f2 = f0/4 So the gravitational force on the satellite after tripling it's altitude is one fourth the original force.</span>

6 0

1 year ago

Stacy measures two quantities: the mass of each washer and the force that the washers exert on the force meter. In general, how

geniusboy [140]

Answer:

When she adds more washers to the meter, the magnitude of force that is shown on the force meter increases.

Explanation:

The force that the washers exert on the force meter is actually the weight of the washers. Weight is actually a force with gravitation acceleration.

F = W = mg

Where g is gravitational acceleration and its value is 9.81 m/s² and m is the mass of any object. As she adds more washers to the meter so the total mass of the washers increases. As the mass of the washers increases, magnitude of the force (Weight) shown on the force meter increases.

6 0

2 years ago

The particle starts from rest at t=0. What is the magnitude p of the momentum of the particle at time t? Assume that t>0. Exp

olganol [36]

Answer:

Ft

Explanation:

We are given that

Initial velocity=u=0

We have to find the magnitude of p of the momentum of the particle at time t.

Let mass of particle=m

Applied force=F

Acceleration, $a=\frac{F}{m}$

Final velocity , $v=a+ut$

Substitute the values

$v=0+\frac{F}{m}t=\frac{F}{m}t$

We know that

Momentum, p=mv

Using the formula

$p=m\times \frac{F}{m}t=Ft$

6 0

2 years ago

7) Three resistors having resistances of 4.0 Ω, 6.0 Ω, and 10.0 Ω are connected in parallel. If the combination is connected in

viva [34]

Answer:

A, 0.59A

Explanation:

The total resistance in the circuit is the resistances in parallel plus that in series.

Total resistance for those in parallel is;

1/(1/4 +1/6 +1/10) = 1/ (15+10+6 /60)

1/(31/60)= 60/31 ohms

Hence total resistance of the circuit is;

60/31 + 2 = (60+62)/31 = 122/31=3.94 ohms

To calculate the current flowing through the 10ohm resistance we need to know the voltage drop by subtracting the voltage drop in the 2ohm resistance from the total voltage drop.

Voltage drop on the 2 ohm resistance is;

Current on the 2 ohm resistor × 2 ohms

V = I ×R ; I - current

R - resistance

Current drop on the 2ohm resistance is;

Total voltage in the circuit/ total resistance in the circuit

12/3.94= 3.05A

Voltage drop on the 2 ohm resistance;

3.05 × 2 = 6.10volts

Hence voltage drop on the parallel resistance would be ;

12-6.10= 5.90V

Now voltage drop in a parallel circuit is the same hence 5.90v is dropped in each of the parallel resistance.

That said, the current drop on the 10 ohm resistor would be;

5.90/10 = 0.59A

Remember V= I× R so that I = V/R

6 0

2 years ago