A woman lifts a barbell 2.0 m in 5.0 s. If she lifts it the same distance in 10 s, the work done by her is:_____

A string that is under 54.0 N of tension has linear density 5.20 g/m . A sinusoidal wave with amplitude 2.50 cm and wavelength 1

kicyunya [14]

Answer:

8.89288275 m/s

Explanation:

F = Tension = 54 N

$\mu$ = Linear density of string = 5.2 g/m

A = Amplitude = 2.5 cm

Wave velocity is given by

$v=\sqrt{\frac{F}{\mu}}\\\Rightarrow v=\sqrt{\frac{54}{5.2\times 10^{-3}}}\\\Rightarrow v=101.90493\ m/s$

Frequency is given by

$f=\frac{v}{\lambda}\\\Rightarrow f=\frac{101.90493}{1.8}\\\Rightarrow f=56.61385\ Hz$

Angular frequency is given by

$\omega=2\pi f\\\Rightarrow \omega=2\pi 56.61385\\\Rightarrow \omega=355.71531\ rad/s$

Maximum velocity of a particle is given by

$v_m=A\omega\\\Rightarrow v_m=0.025\times 355.71531\\\Rightarrow v_m=8.89288275\ m/s$

The maximum velocity of a particle on the string is 8.89288275 m/s

5 0

3 years ago

A satellite of mass m completes one revolution around the earth at a constant speed s and radius r.

MAXImum [283]

Answer:

d. The magnitude of the work done by the earth on the satellite is non zero

Explanation:

The work done is equal to the product of the force and the distance moved in the direction of the force, the force and the distance act perpendicular to one another, therefore no work is done in the circular motion of the movement of the earth.

8 0

3 years ago

According to Lenz's law, the induced current in a circuit always flows to oppose the external magnetic field through the circuit

Makovka662 [10]

Answer:

True.

Explanation:

According to Lenz's law, the induced current in a circuit always flows to oppose the external magnetic field through the circuit. This statement is true.

The Faraday's law of induction is given by :

$\epsilon=-\dfrac{d\phi}{dt}$

Here, negative sign shows that the direction of induced emf is such that opposes the changing current that is its cause.

Hence, the statement is true.

3 0

3 years ago

A flexible balloon contains 0.400 molmol of an unknown polyatomic gas. Initially the balloon containing the gas has a volume of

Nastasia [14]

Answer:

Mass released = 8.6 g

Given data:

Initial number of moles nitrogen= 0.950 mol

Initial volume = 25.5 L

Final mass of nitrogen released = ?

Final volume = 17.3 L

Formula:

V₁/n₁ = V₂/n₂

25.5 L / 0.950 mol = 17.3 L/n₂

n₂ = 17.3 L× 0.950 mol/25.5 L

n₂ = 16.435 L.mol /25.5 L

n₂ = 0.644 mol

Initial mass of nitrogen:

Mass = number of moles × molar mass

Mass = 0.950 mol × 28 g/mol

Mass = 26.6 g

Final mass of nitrogen:

Mass = number of moles × molar mass

Mass = 0.644 mol × 28 g/mol

Mass = 18.0 g

Mass released = initial mass - final mass

Mass released = 26.6 g - 18.0 g

Mass released = 8.6 g

Read more on Brainly.com - brainly.com/question/15623698#readmore

7 0

3 years ago

A parallel-plate capacitor in air has a plate separation of 1.76 cm and a plate area of

Monica [59]

Answer:

Explanation:

Plate separation, d = 1.76 cm = 0.0176 m

Area of plates, A = 25 cm^2 = 0.0025 m^2

V = 255 V

(a) Capacitance of capacitor

$C = \frac{\epsilon _0A}{d}$

$C = \frac{8.854\times 10^{-12}\times 0.0025}{0.0176}$

C = 1.258 x 10^-12 F

charge is same before and after immersion as the battery is disconnected

q = C V

q = 1.258 x 10^-12 x 255 = 3.2 x 10^-10 C

(b)

Capacitance before, C = 1.258 x 10^-12 C

capacitance after, C' = k x C = 80 x 1.258 x 10^-12 = 100.64 x 10^-12 C

Where, k is the dielectric constant of water = 80

Potential difference after immersion, V' = V / k = 255 / 80 = 3.1875 V

(c) initial energy,

$U = \frac{q^{2}}{2C}$

$U = \frac{(3.2\times 10^{-10})^{2}}{2\times 1.258\times 10^{-12 }}=4.07\times 10^{-8}J$

Final energy

$U' = \frac{q^{2}}{2C'}$

$U' = \frac{(3.2\times 10^{-10})^{2}}{2\times 100.64\times 10^{-12}}=5.08\times 10^{-10}J$

6 0

3 years ago

A woman lifts a barbell 2.0 m in 5.0 s. If she lifts it the same distance in 10 s, the work done by her is:______