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IRISSAK [1]
3 years ago
13

What element is used as a source of radiation in smoke detectors?

Physics
1 answer:
mart [117]3 years ago
4 0
Americium ( A source of alpha radiation to detect and identify smoke.)
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A football player is running with a velocity or 10 m/s. At that velocity, his momentum is 2500 kg*m/s. What is the football play
DedPeter [7]

The mass of the football player is 250 kg.

<u>Explanation:</u>

Momentum is defined as the product of mass and velocity. So here the velocity (v) is given as 10 m/s and the momentum is given as 2500 kg m /s. So we can determine the mass (m) of the player by substituting the known terms in the formula of determining momentum as shown below.

             \text {Momentum}(p)=m \times v

As we know the value of momentum and velocity, the mass can be found as,

             m=\frac{p}{v}=\frac{2500}{10}=250 \mathrm{kg}

Thus, the mass of the football player is found to be 250 kg.

7 0
3 years ago
The impulse given to a ball with mass of 4 kg is 28 N s. If the ball were already moving at 3 m/s what would the final velocity
mart [117]

vf = 10 m/s. A ball with mass of 4kg and a impulse given of 28N.s with a  intial velocity of 3m/s would have a final velocity of 10 m/s.

The key to solve this problem is using the equation I = F.Δt = m.Δv, Δv = vf - vi.

The impulse given to the ball with mass 4Kg is 28 N.s. If the ball were already moving at 3 m/s, to calculate its final velocity:

I = m(vf - vi) -------> I = m.vf - m.vi ------> vf = (I + m.vi)/m ------> vf = I/m + vi

Where I 28 N.s, m = 4 Kg, and vi = 3 m/s

vf = (28N.s/4kg) + 3m/s = 7m/s + 3m/s

vf = 10 m/s.

.

6 0
3 years ago
The concept of critical density is just like the idea of escape velocity for a projectile launched from the earth. An object lau
ikadub [295]

Answer:

v = √ 2 G M/ R_{e}

Explanation:

To find the escape velocity we can use the concept of mechanical energy, where the initial point is the surface of the earth and the end point is at the maximum distance from the projectile to the Earth.

Initial

        Em₀ = K + U₀

Final

        Em_{f} =  U_{f}

The kinetic energy is k = ½ m v²

The gravitational potential energy is U = - G m M / r

r is the distance measured from the center of the Earth

How energy is conserved

       Em₀ =  Em_{f}

       ½ mv² - GmM / R_{e} = -GmM / r

       v² = 2 G M (1 /  R_{e} – 1 / r)

       v = √ 2GM (1 / R_{e} – 1 / r)

The escape velocity is that necessary to take the rocket to an infinite distance (r = ∞), whereby 1 /∞ = 0

        v = √ 2GM /  R_{e}

5 0
3 years ago
What does that make?
Kobotan [32]

Answer:

lithium

Explanation:

A lithium atom contains 3 protons in its nucleus irrespective of the number of neutrons or electrons. Notice that because the lithium atom always has 3 protons, the atomic number for lithium is always 3. The mass number, however, is 6 in the isotope with 3 neutrons, and 7 in the isotope with 4 neutrons.

7 0
3 years ago
Read 2 more answers
The amount of heat energy required to raise the temperature of a unit mass of a material one degree is
charle [14.2K]
The amount of heat energy required to raise the temperature of a unit mass of a material to one degree is called D. its heat capacity.

The relationship of the heat when applied to the object and the change in temperature of the object when heat is being applied is directly proportional to each other. This means that when heat is applied to the object, the temperature of the object increases and when heat is not applied to the object, the temperature of the object decreases.
5 0
3 years ago
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