1answer.
Ask question
Login Signup
Ask question
All categories
  • English
  • Mathematics
  • Social Studies
  • Business
  • History
  • Health
  • Geography
  • Biology
  • Physics
  • Chemistry
  • Computers and Technology
  • Arts
  • World Languages
  • Spanish
  • French
  • German
  • Advanced Placement (AP)
  • SAT
  • Medicine
  • Law
  • Engineering
VladimirAG [237]
2 years ago
7

Can someone help me with this Physics question please?

Physics
2 answers:
Ghella [55]2 years ago
7 0

How many half-lifes is 49.2 years ?

(49.2 years) / (12.3 years per half-life)  =  4 half-lifes.

In 4 half-lifes, (1/2) · (1/2) · (1/2) · (1/2) of the original sample remains.

That's (1/2⁴) or (1/16) of the original.

(1/16) of 48.0 mg  =  <em>3 mg</em> .

=======================

Step-by-step:

== Start with 48 mg .

== After one half-life, 24 mg remains.

== Then, after the second half-life, 12 mg remains.

== Then, after the third half-life, 6 mg remains.

== Then, after the fourth half-life, <em>3 mg</em> remains.

strojnjashka [21]2 years ago
6 0

Answer:

Explanation:

The formula for this, the easy one, is

N=N_0(\frac{1}{2})^{\frac{t}{H} where No is the initial amount of the element, t is the time in years, and H is the half life. Filling in:

N=48.0(\frac{1}{2})^{\frac{49.2}{12.3} and simplifying a bit:

N=48.0(.5)^4 and

N = 48.0(.0625) so

N = 3 mg left after 12.3 years

You might be interested in
A boxer can hit a heavy bag with great force. Why can't he hit a piece of tissue paper in midair with the same amount of force?
12345 [234]

Answer:

This is due to impulse

Explanation:

Impulse equal to mΔv and FΔt

You can set these equal as mΔv = FΔt

When a boxer punches a tissue, it is like punching a cushion or a pillow. The time that the hit takes is much grater than if they were to hit something solid. In addition, the change in velocity of the boxer's arm would be much greater when they hit a punching bag. In this equation, the greater the time, the less force that is needed.

6 0
3 years ago
When the Glen Canyon hydroelectric power plant in Arizona is running at capacity, 690 m3 of water flows through the dam each sec
igomit [66]

Answer:

The maximum electric power output is P_{max} =1.339*10^{9} \ W

Explanation:

From the question we are told that

        The capacity of the hydroelectric plant is \frac{V}{t}   =  690 \ m^3 /s

         The level at which water is been released is h  =  220 \ m

        The efficiency is  \eta  =0.90

       

The electric power output is mathematically represented as

       P  = \frac{PE_l - PE _o}{t}

Where  PE_l is the potential energy at  level h which is mathematically evaluated as  

          PE_l  =  mgh

and  PE_o  is  the potential energy at ground level which is mathematically evaluated as  

          PE_o  =  mg(0)

         PE_o  =  0

So  

         P  = \frac{mgh}{t}

here  m  =   V *  \rho

where V is volume  and  \rho is density of water whose value is  \rho = 1000 kg/m^3

 So  

         P  = \frac{(\rho * V) * gh}{t}

        P  = \frac{V}{t} * gh \rho

substituting values  

       P  =690 * 9.8 * 220 * 1000

      P  =1.488*10^{9} \ W

The maximum possible electric power output is

           P_{max} = P * \eta

substituting values  

         P_{max} =1.488*10^{9} * 0.90

         P_{max} =1.339*10^{9} \ W

6 0
2 years ago
A car's gas tank contains 58.7 kg
Bogdan [553]

Answer:

721 kg/m^3

Explanation:

Trust me bro

8 0
3 years ago
(1 point) A projectile is fired from ground level with an initial speed of 600 m/sec and an angle of elevation of 30 degrees. Us
konstantin123 [22]

Answer:

(a) The range of the projectile is 31,813.18 m

(b) The maximum height of the projectile is 4,591.84 m

(c) The speed with which the projectile hits the ground is 670.82 m/s.

Explanation:

Given;

initial speed of the projectile, u = 600 m/s

angle of projection, θ = 30⁰

acceleration due to gravity, g = 9.8 m/s²

(a) The range of the projectile in meters;

R = \frac{u^2sin \ 2\theta}{g} \\\\R = \frac{600^2 sin(2\times 30^0)}{9.8} \\\\R = \frac{600^2 sin (60^0)}{9.8} \\\\R = 31,813.18 \ m

(b) The maximum height of the projectile in meters;

H = \frac{u^2 sin^2\theta}{2g} \\\\H = \frac{600^2 (sin \ 30)^2}{2\times 9.8} \\\\H = \frac{600^2 (0.5)^2}{19.6} \\\\H = 4,591.84 \ m

(c) The speed with which the projectile hits the ground is;

v^2 = u^2 + 2gh\\\\v^2 = 600^2 + (2 \times 9.8)(4,591.84)\\\\v^2 = 360,000 + 90,000.064\\\\v = \sqrt{450,000.064} \\\\v = 670.82 \ m/s

5 0
2 years ago
PLZ HELP I WILL GIVE BRAINLIEST
Vaselesa [24]

Answer:

12.7m/s

Explanation:

Given parameters:

Mass of diver  = 77kg

Height of jump  = 8.18m

Unknown:

Final velocity  = ?

Solution:

To solve this problem, we apply the motion equation below:

             v²   = u²  + 2gH

v is the final velocity

u is the initial velocity

g is the acceleration due to gravity

H is the height

 Now insert the parameters and solve;

       v² = 0²  +  2 x 9.8 x 8.18

     v  = 12.7m/s

8 0
2 years ago
Other questions:
  • Technician A states that accidents avoidance is an additional feature on some electronic stability control systems. Technician B
    7·1 answer
  • Which of the following is true about a rigid body in dynamic equilibrium? The body can have translational motion, but it cannot
    10·1 answer
  • The planet Venus, our moon, and Halley's Comet all
    15·2 answers
  • What is the best explanation of the importance of the Eighth Amendment?
    7·2 answers
  • Which term describes the amount of charge that passes a point in a circuit<br> each second?
    12·2 answers
  • Two objects have the same size and shape, but one is much heavier than the other. When they are dropped simultaneously from a to
    13·1 answer
  • Helppppppppp
    10·2 answers
  • Explain why it is easy to slip on a floor that is wet please, I need this answered now if anyone can.
    7·2 answers
  • What's the average speed of an object moving 3790 meters in 249 s.
    12·1 answer
  • All power plants use fuel to supply energy that turns into:
    12·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!