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3 years ago

I have no idea so i'm screwed please help me

Physics

1 answer:

podryga [215]3 years ago

8 0

Answer:

Let N0 be the initial atoms of Be11

N0 / 2^1 = N0 / 2 Number of Be11 after 1 half-life

N0 / 2^2 = N0/ 4 Number of Be11 after 2 half-lives

30/13.81 = 2.17 half lives

N0 / 2^2.17 = N0 / 4.51 = .222 N0 or 22.2 % of atoms remain

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Serhud [2]

Answer:

v = 21.4m/s

Explanation:

Given r1 = < 13, -18, -2 > m,

F = < 250, 390, -220 > N, r2 = < 19, -23, -5 > m

Where r1 and r2 are position vectors in space and F is the constant force vector in space.

r2 - r1 = < 19–13, -23–(-18), -5–(-2) > m

Δr = < 6, -5, -3 > m

F = m×a

a = F/m

m = 110kg (scalar quantity)

a = < 250/110, 390/110, -220/110 >

a = < 2.27, 3.55, -2 > m/s²

Since the force is constant, the acceleration is also constant. Therefore the equations of constant acceleration motion apply here.

V² = u² +2aΔr

The magnitude of the acceleration is calculated as follows

a = √(2.27² + 3.55² +(-2)²)

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Magnitude of Δr,

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Having calculated the magnitude of the acceleration and displacement, we can now calculate the final velocity.

u = initial velocity = 19.5m/s

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3 years ago

Which three quantities can be used to calculate acceleration?

PtichkaEL [24]

D is the correct answer, assuming that this is the special case of classical kinematics at constant acceleration. You can use the equation V = Vo + at, where Vo is the initial velocity, V is the final velocity, and t is the time elapsed. In D, all three of these values are given, so you simply solve for a, the acceleration.
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4 years ago

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Answer:

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Explanation:

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