How many half-lives must go by for the radioactivity of this isotope to drop to (1/512) of its original value?

The filament of a certain lamp has a resistance that increases linearly with temperature. When a constant voltage is switched on

Neporo4naja [7]

Answer:

162.8 K

Explanation:

initial current = io

final current, i = io/8

Let the potential difference is V.

coefficient of resistivity, α = 43 x 10^-3 /K

Let the resistance is R and the final resistance is Ro.

The resistance varies with temperature

R = Ro ( 1 + α ΔT)

V/i = V/io (1 + α ΔT )

8 = 1 + 43 x 10^-3 x ΔT

7 = 43 x 10^-3 x ΔT

ΔT = 162.8 K

Thus, the rise in temperature is 162.8 K.

5 0

2 years ago

In an Atwood's machine, one block has a mass of 602.0 g, and the other a mass of 717.0 g. The pulley, which is mounted in horizo

Wittaler [7]

Answer:

The acceleration of the both masses is 0.0244 m/s².

Explanation:

Given that,

Mass of one block = 602.0 g

Mass of other block = 717.0 g

Radius = 1.70 cm

Height = 60.6 cm

Time = 7.00 s

Suppose we find the magnitude of the acceleration of the 602.0-g block

We need to calculate the acceleration

Using equation of motion

$s=ut+\dfrac{1}{2}at^2$

Where, s = distance

t = time

a = acceleration

Put the value into the formula

$60.0\times10^{-2}=0+\dfrac{1}{2}\times a\times(7.00)^2$

$a=\dfrac{60.0\times10^{-2}\times2}{(7.00)^2}$

$a=0.0244\ m/s^2$

Hence, The acceleration of the both masses is 0.0244 m/s².

5 0

3 years ago

A truck is carrying a steel beam of length 13.0 m on a freeway. An accident causes the beam to be dumped off the truck and slide

PIT_PIT [208]

Answer:

$emf= 9.88 \times 10^{-3} T$

Explanation:

Given:

Length of the beam, $l=13\,m$

speed of the beam, $v=20\,m.s^{-1}$

magnitude of the vertical magnetic field, $B=38\times 10^{-6} T$

According to the Faraday's law the emf induced in a rod passing transversely through a magnetic field is given as:

$emf= l.v.B$

$emf=13\times 20\times 38\times 10^{-6}$

$emf= 9.88 \times 10^{-3} T$

4 0

2 years ago

A 50 n force is acting on a lever 1.5 m from the fulcrum balances an object 1m from the fulcrum on the other arm. what is the we

Angelina_Jolie [31]

Answer:

A 100 N force acting on a lever 2 m from the fulcrum balances an object 0.5 m from the fulcrum on. ... What is the weight of the object(in newtons)? What is its mass (in kg)? ... mass at the one end and effort arm is the distance between pivot and effort applied at the other end.

Explanation:

hpoe this helps you.

4 0

2 years ago

A person having a mass of 85 kg sits on the edge of a horizontal rotating platform, 2.2 m from the center of the platform, and h

gulaghasi [49]

The angular momentum of the person is given by:
$L=mvr$
where $m=85 Kg$ is the mass of the person, $v=6.6 m/s$ is the tangential velocity, and $r=2.2 m$ is the distance of the person from the center of rotation. Using these data, we find
$L=(85 Kg)(6.6 m/s)(2.2 m)=1234.2 Kg \cdot m^2/s$

3 0

2 years ago