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2 years ago

5) Choose the best revision of the following statement: "All the isotopes of a particular element decay radioactively by

Physics

1 answer:

tino4ka555 [31]2 years ago

5 0

Answer:

B. some isotopes are stable and others are unstable. unstable isotopes decay by emitting various subatomic particles and radiation.

Explanation:

test gave me the answer so yeah :/ XD

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Twist-on connectors without the spring-steel coils (plastic threads only) are suitable for making branch-circuit connections.

Gnoma [55]

Answer:

if it is a plastic connector it wont work but if there is metal or steel it will work

Explanation:

6 0

3 years ago

Which term is defined as a change in an object's position relative to a reference point?

Gre4nikov [31]

The answer would be REFERENCE POINT

4 0

3 years ago

Read 2 more answers

How much does it cost to leave a porch light on all night?

worty [1.4K]

Cost = (0.001) x (the wattage of the light) x (the number of hours it's left on) x (the cost of each kilowatt-hour of electrical energy where you live).

6 0

3 years ago

n 38 g rifle bullet traveling at 410 m/s buries itself in a 4.2 kg pendulum hanging on a 2.8 m long string, which makes the pend

Kitty [74]

Answer:

68cm

Explanation:

You can solve this problem by using the momentum conservation and energy conservation. By using the conservation of the momentum you get

$p_f=p_i\\mv_1+Mv_2=(m+M)v$

m: mass of the bullet

M: mass of the pendulum

v1: velocity of the bullet = 410m/s

v2: velocity of the pendulum =0m/s

v: velocity of both bullet ad pendulum joint

By replacing you can find v:

$(0.038kg)(410m/s)+0=(0.038kg+4.2kg)v\\\\v=3.67\frac{m}{s}$

this value of v is used as the velocity of the total kinetic energy of the block of pendulum and bullet. This energy equals the potential energy for the maximum height reached by the block:

$E_{fp}=E_{ki}\\\\(m+M)gh=\frac{1}{2}mv^2$

g: 9.8/s^2

h: height

By doing h the subject of the equation and replacing you obtain:

$(0.038kg+4.2kg)(9.8m/s^2)h=\frac{1}{2}(0.038kg+4.2kg)(3.67m/s)^2\\\\h=0.68m$

hence, the heigth is 68cm

4 0

3 years ago

Match the following:

joja [24]

Explanation:

1. study of conversion of heat to mechanics → thermodynamics

A branch of physical science which deals with heat and other forms of energy.

2. The Law of Conservation of Energy → first Law of Thermodynamics

Energy cannot be created nor be destroyed. According to first law of thermodynamics total energy of the system is always constant.

3. Result of applied energy → work

Work is the way of system to release its energy.

4. Principle that states that in any energy transformation some energy is dissipated as heat → Second Law of Thermodynamics

5. energy of motion → kinetic energy

Kinetic energy is defined as energy possessed by the body due to its motion.

6. work/displacement → force

Work is product of force and displacement.

$Work=Force \times displacement$

$Force=\frac{Work}{displacement}$

7. power · time → energy

Power is defined energy per unit time.

$Power=\frac{Energy}{Time}$

$Energy=Power\times Time$

8. Device that transforms heat energy into mechanical energy → heat engine

heat engine is a device which converts the heat energy which is released due to combustion of fuel into a useful work that is mechanical energy.

9 . Energy due to position → potential energy

Potential energy is defined as energy possessed by the body due to its position.

10. efficiency of a heat engine unit of heat → calorie

11. Measure of molecular motion → Temperature

Kinetic energy is directly proportional to temperature.

Greater the motion more will be the kinetic energy and with more will be the temperature.

12. Heat given off by a liquid with no change in temperature → latent heat of fusion

Latent heat of fusion is defined as heat released by 1 mole of substance when it under goes phase change that is from solid to liquid.

13. Motion within solids → vibrational motion

Vibrational motion is the motion in which particle oscillates from its mean position.

14. Phase of matter on the sun → plasma

Plasma is hot ionized gas with equal number of positive and negative ions. Due to high temperature of sun most the gas are in the plasma state.

8 0

3 years ago