a radioactive tracer has a half-life of 2 hours. how much of a 2500g sample will be avalible after 18 hours

Suppose a plane accelerates from rest for 30 s, achieving a takeoff speed of 80 m/s after traveling a distance of 1200 m down th

Margaret [11]

Answer:

300 m

Explanation:

The train accelerate from the rest so u = 0 m/sec

Final speed that is v = 80 m/sec

Time t = 30 sec

The distance traveled by first plane = 1200 m

We know the equation of motion $S=ut+\frac{1}{2}at^2$ where s is distance a is acceleration and u is initial velocity

Using this equation for first plane $1200=0\times 30+\frac{1}{2}a30^2$

$a=2.67\frac{m}{sec^2}$

As the acceleration is same for both the plane so a for second plane will be 2.67 $\frac{m}{sec^2}$

The another equation of motion is $v^2=u^2+2as$ using this equation for second plane $40^2=0+2\times 2.67\times s$

s = 300 m

5 0

2 years ago

A planned high-speed train between Houston and Dallas will travel a distance of 386 kilometers in 5.40 × 10^3 seconds. What is t

Mazyrski [523]

¡Hellow!

For this problem, first, lets convert the seconds in hours:

5,4x10³ $\rightarrow$ 5400

h = sec / 3600

h = 5400 s / 3600

h = 1,5

Let's recabe information:

d (Distance) = 386 km

t (Time) = 1,5 h

v (Velocity) = ?

For calculate velocity, let's applicate formula:

$\boxed{\boxed{\textbf{d = v * t} } }$

Reeplace according we information:

386 km = v * 1,5 h

v = 386 km / 1,5 h

v = 257,33 km/h

The velocity of the train is of <u>257,33 kilometers for hour.</u>

<u></u>

Extra:

For convert km/h to m/s, we divide the velocity of km/h for 3,6:

m/s = km/h / 3,6

Let's reeplace:

m/s = 257,33 km/h / 3,6

m/s = 71,48

¿Good Luck?

7 0

3 years ago

A penny is dropped off the top of the Stratosphere from rest and falls freely with the

Roman55 [17]

Answer:

S = 122.5m

Explanation:

Given the following data;

Acceleration due to gravity = 9.8m/s²

Time, t = 5 seconds

Since it's a free fall, initial velocity, u = 0

To find the displacement, we would use the second equation of motion given by the formula;

$S = ut + \frac {1}{2}at^{2}$

Where;

S represents the displacement or height measured in meters.

u represents the initial velocity measured in meters per seconds.

t represents the time measured in seconds.

a represents acceleration measured in meters per seconds square.

Substituting into the equation, we have;

$S = 0*5 + \frac {1}{2}*(9.8)*5^{2}$

$S = 0 + 4.9*25$

S = 122.5m.

3 0

3 years ago

If blue light hits a red filter, what kind of light comes through the filter?

kotegsom [21]

It can be either C or B

Reasons it can be C: Red and Blue together(if I'm correct in art) is the combined color of two of the 3 primary colors to get a purple/violet color and if said filter is see through or just too dense for the light to even penetrate the said filter(in theory) but all in all purple is the answer with the two primary colors blue and red.

But also, it depends on what kind of filter it is, if the filter is like a screen filter then it will just come out in blue with the slightly different colors of again purple but in a darker tone then the actual eye can see.

Or it can be just C again cause the filter can be a film but that's a bit too far and to complex for right now so I believe it is B

8 0

3 years ago

A helium-filled balloon is launched when the temperature at ground level is 27.8°c and the barometer reads 752 mmhg. if the ball

ololo11 [35]

The helium may be treated as an ideal gas, so that
(p*V)/T =constant
where
p = pressure
V = volume
T = temperature.

Note that
7.5006 x 10⁻³ mm Hg = 1 Pa
1 L = 10⁻³ m³

Given:
At ground level,
p₁ = 752 mm Hg
= (752 mm Hg)/(7.5006 x 10⁻³ mm Hg/Pa)
= 1.0026 x 10⁵ Pa
V₁ = 9.47 x 10⁴ L = (9.47 x 10⁴ L)*(10⁻³ m³/L)
= 94.7 m³
T₁ = 27.8 °C = 27.8 + 273 K
= 300.8 K

At 36 km height,
P₂ = 73 mm Hg = 73/7.5006 x 10⁻³ Pa
= 9.7326 x 10³ Pa
T₂ = 235 K

If the volume at 36 km height is V₂, then
V₂ = (T₂/p₂)*(p₁/T₁)*V₁
= (235/9.7326 x 10³)*(1.0026 x 10⁵/300.8)*94.7
= 762.15 m³

Answer: 762.2 m³

3 0

3 years ago