2. A stone is thrown upwards with an initial velocity of 25 m/s at

A woman standing before a cliff claps her hands, and 2.8s later she hears the echo. How far away is the cliff? The speed of soun

ella [17]

Answer:

480.2 m

Explanation:

The following data were obtained from the question:

Speed of sound (v) = 343 m/s.

Time (t) = 2.8 s

Distance (x) of the cliff =?

The distance of the cliff from the woman can be obtained as follow:

v = 2x /t

343 = 2x /2.8

Cross multiply

2x = 343 × 2.8

2x = 960.4

Divide both side by the coefficient of x i.e 2

x = 960.4/2

x = 480.2 m

Therefore, the cliff is 480.2 m away from the woman.

4 0

3 years ago

A parallel-plate capacitor with circular plates of radius 0.10 m is being discharged. A circular loop of radius 0.20 m is concen

Sedaia [141]

Answer:

7.1934 x 10^12 V/m.s

Explanation:

In order to do this exercise, you need to use the correct formula. Besides that, we need to identify our data.

First we have the radius of the plates which are circular, and it's 0.1 m. The current of the loop (I) is 2.0 A, and the radius of the loop is 0.2 m.

Now with this data, we use the next formula:

I = dE/dt Eo A

Where:

dE/dt = rate of electric field

Eo = constant of permittivity of free space

A = Area of circle

Solving for dE/dT:

dE/dt = I / Eo*A

Now, the area of the circle is A = πr²

A = 3.1416 * (0.1)² = 0.031416 m²

Now solving the electric field:

dE/dt = 2 / (8.85x10^-12 * 0.031416)

dE/dt = 7.1934 x 10^12 V/m.s

6 0

3 years ago

Coal is an example of kinetic or potential energy

pav-90 [236]

Answer:

Potential energy

Explanation:

4 0

3 years ago

Read 2 more answers

In a science fiction novel two enemies, Bonzo and Ender, are fighting in outer spce. From stationary positions, they push agains

Bingel [31]

Answer:

2.461

Explanation:

Let mass of Bonzo = m1

Mass of Ender =m2

When they push eachother from stationary position

Initial velocity of Bonzo = Vib=0 m/s

Final velocity of Bonzo = Vfb= 1.3 m/s

Initial velocity of Ender = Vie= 0 m/s

Final velocity of Ender = Vfe= -3.1 m/s

We know initial momentum = final momentum

==> m1Vib+m2Vie = m1Vfb+m2Vfe

==> 0+0= m1×1.3 +m2×(-3.1)

==> 1.3m1-3.1m2=0

==> 1.3 m1 = 3.2 m2

==> m1/m2 = 3.2/1.3

==> m1/m2 = 2.461

6 0

3 years ago

Write the differential equation that governs the motion of the damped mass-spring system, and find the solution that satisfies t

melisa1 [442]

This question is incomplete, the complete question is;

Write the differential equation that governs the motion of the damped mass-spring system, and find the solution that satisfies the initial conditions specified. Units are mks; γ is the damping coefficient, with units of kg/sec

m = 0.2, γ = 1.6 and k = 4

Initial displacement is 1 and initial velocity is -2

x" + _____ x' ____x = 0

x(t) =

Answer:

the solution that satisfies the initial conditions specified is;

x(t) = $c_1e^{-4t}cos(2t)$ + $c_2e^{-4t}sin(2t)$

Explanation:

Given the data in the question ;

m = 0.2, γ = 1.6, k = 4

x(0) = 1, x'(0) = -2

Now, the differential equation that governs the motions of spring mass system is;

mx" + γx' + kx = 0

so we substitute

0.2x" + 1.6x' + 4x = 0

divide through by 0.2

x" + 8x' + 20x = 0

hence, characteristics equation will be;

m² + 8m + 20 = 0

we find m using; x = [ -b±√(b² - 4ac) ] / 2a

m = [ -8 ± √((8)² - 4(1 × 20 )) ] / 2(1)

m = [ -8 ± √( 64 - 80 ) ] / 2

m = [ -8 ± √-16 ) ] / 2

m = ( -8 ± 4i ) / 2

m = -4 ± 2i

Hence, the general solution of the differential equation is;

x(t) = $c_1e^{-4t}cos(2t)$ + $c_2e^{-4t}sin(2t)$

From the initial conditions;

c₁ = 1, c₂ = 1

the solution that satisfies the initial conditions specified is;

x(t) = $c_1e^{-4t}cos(2t)$ + $c_2e^{-4t}sin(2t)$

6 0

3 years ago