How will the world end?

You have a radioactive sample with a half-life of 1 hour. At t = 1 hour, a Geiger counter measures its radiation at 40 counts/mi

Mama L [17]

Answer:

Explanation:

Given that, .

The half-life of a radioactive element is

t½ = 1 hr.

At the first hour, the radioactive element has 40 counts/minute

After 4 hours it has 5 counts/minute

So,

We want to filled the table.

0 hours, I.e at the start

40 counts/mins × 2 = 80 counts / mis

First half-life (first hour) is

40 counts/mins

Second half-life (second hour)

40 counts/mins × ½ = 20 counts/mins

Third half-life (third hour)

40 counts/mins × ¼ = 10 counts / mins

Fourth half life (fourth hour)

40 counts/mins × ⅛ = 5 counts / mins

So, the table is

Time........................Geiger Counter Rate

0 hours.................... 80 counts / minutes

1 hour........................ 40 counts / minutes

2 hours..................... 20 counts / minutes

3 hours..................... 10counts / minutes

4 hours...................... 5 counts / minute

6 0

3 years ago

Can anyone Hele please I don't know how to convert the light years in order to get an equation like the one on Alpha Centauri in

Svetradugi [14.3K]

Answer:

Log 10 ( 4.16x10^16)

Explanation:

Other distance from sun you have to search by your self then apply the equation Log 10 ( distance from sun )

4 0

3 years ago

1. the change in position of an object from start to finish, a vector quantity model 2. a portion of space that contains a value

VladimirAG [237]

1. the change in position of an object from start to finish, a vector quantity . . . . . displacement

2. a portion of space that contains a value for a measurable quantity at every point in space . . . . . field

3. speed = (distance) / (time to cover the distance)

4. the length of the entire path an object travels from start to finish . . . . . distance

5. a measurement that has both magnitude and direction . . . . . vector

6. a change in displacement with respect to time . . . . . velocity

7. a mental or physical construct or description that describes a physical phenomenon . . . . . model

8. a change in velocity with respect to time . . . . . acceleration

9. a measurement that only expresses magnitude, such as time, temperature, distance, and speed . . . . . scalar

10. objects that are thrown or launched in the air and are subject to gravity . . . . . projectile

8 0

4 years ago

Read 2 more answers

A well-insulated electric water heater warms 131 kg of water from 20.0°C to 51.0°C in 31.0 min. Find the resistance (in Ω) of it

Nookie1986 [14]

Answer:

Explanation:

Heat required to warm the water from 20 degree to 51 degree

= mct

= 131 x 4150 x ( 51 - 20 )

= 16853150 J

Power of heating element

= v² /R

Heat generated in 31 min

= (v² / r ) x 31 x 60 = 16853150

r = (240 x 240 x 31 x 60) / 16853150

6.35 ohm

In this case heat required will change so time will also change

Heat required =

131 x 4150 x ( 100-51 )

= 26638850 J

If time required be t hour

Energy consumed

Power x time

= (v² / r ) x t x 60 = 26638850

t = 26638850 x 6.35 / (240 x 240 x 60 )

= 48.95 h

Heat required to evaporate water at 100 degree

= mass x latent heat

= 131 x 2260000

= 296060000 J

Total heat required

= 296060000 + 26638850 + 16853150

= 339552000 J

time required = 339552000 x 6.35 / (240 x 240 x 60 )

= 623.88 h .

3 0

3 years ago

A 15-kg block at rest on a horizontal frictionless surface is attached to a very light ideal spring of force constant 450 N/m. T

den301095 [7]

Answer:

0.266 m

Explanation:

Assuming the lump of patty is 3 Kg then applying the principal of conservation of linear momentum,

P= mv where p is momentum, m is mass and v is the speed of an object. In this case

$m_pv_p=v_c(m_p+m_b)$ where sunscripts p and b represent putty and block respectively, c is common velocity.

Substituting the given values then

3*8=v(15+3)

V=24/18=1.33 m/s

The resultant kinetic energy is transferred to spring hence we apply the law of conservation of energy

$0.5(m_p+m_b)v_c^{2}=0.5kx^{2}$ where k is spring constant and x is the compression of spring. Substituting the given values then

$(3+15)*1.33^{2}=450*x^{2}\\x\approx 0.266 m$

7 0

3 years ago