We use the radioactive decay equation for this problem which is expressed as:
An = Aoe^-kt
An is the remaining amount after time t, Ao is the initial amount and k is a constant.
First, we determine the k from the half life as follows:
An/Ao = 1/2 = e^-k(14.4)
k = 0.04814
Then, we can calculate An after 28.8 yr.
An = 1000 e^-0.04814(28.8)
An = 250 g
Answer:
, pfx = pix + Jx.
Explanation:
The momentum principle tells us that impulse transfers momentum to an object.
If an object has 2 kgm/s of momentum, a 1 kgm/s impulse delivered to the object
increases its momentum to 3 kgm/s. That is, pfx = pix + Jx.
Just as we did with energy, we can represent this “momentum accounting” with a
momentum bar chart. For example, the bar chart of FIGURE 11.6 represents the ball
colliding with a wall in Figure 11.4. Momentum bar charts are a tool for visualizing
an interaction
Answer:
550 kN
Explanation:
Pressure = force/area
∴ Force = pressure x area.
F = 1,100 × 10^3 × 0.5 = 550,000 N
F = 550 kN
Temperature in Kelvin = 41+273 = 314K
Volume in liter = 11/1000 = 0.011L
Pressure in atmosphere = 790 mmhg = 1atm
Gas constant(R) = 0.082 L-atm-K⁻¹-mol⁻¹
Using ideal gas law equation,
PV=nRT
1×0.011 = n×0.082×314
n = 0.011/0.082×314
n = 4.27×10⁻⁴ moles.
∴ mass of helium gas required = n×4 = 4.27×10⁻⁵×4 = 1.708×10⁻⁴ gram.
Answer: Rick and Mike are going in opposite directions. Then the distance between them as a function of time will be R = Vm*(time traveled) + Vr*(time traveled).
where Vm is the velocity of mike, Vr is the velocity of rick
then, if after 1 hour and 30 mins the distance between them is 210 miles.
we have 250 miles = Vm*1.5 h + Vr*1.5 h
i used 1.5 hours, because 1 hour and 30 minutes are 1.5 hours.
We also know that Vm = Vr + 8 miles.
so: 250 miles = Vr*1.5h + (Vr + 8miles/hour)*1.5 = (2*vr + 8miles)*1.5h
250/1.5 miles/hour - 8 miles/hour = 2*Vr = 158.66 miles per hour.
then Vr = 158.66 /2 = 79.33 miles per hour.
and Vm = (79.33 + 8) = 87.33 miles per hour.