Answer:
A 1.0 min
Explanation:
The half-life of a radioisotope is defined as the time it takes for the mass of the isotope to halve compared to the initial value.
From the graph in the problem, we see that the initial mass of the isotope at time t=0 is
The half-life of the isotope is the time it takes for half the mass of the sample to decay, so it is the time t at which the mass will be halved:
We see that this occurs at t = 1.0 min, so the half-life of the isotope is exactly 1.0 min.
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.
7. power · time → energy
Power is defined energy per unit 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.
Answer:
(a)
(b)
(c)
Explanation:
Given that,
(a) An electron accelerated from rest through a potential difference of 100 V. The De Broglie wavelength in terms of potential difference is given by :
Where
m and e are the mass of and charge on an electron
On solving,
V = 100 V
(b) V = 1 kV = 1000 V
(c) If
Hence, this is the required solution.
Answer:
1.when it is closest to the sun
2.when it is midway between its farthest
Explanation:
According to the law of Kepler's
T ² ∝ r³
T=Time period
r=semi major axis
We also know that time period T given as
v=Speed
So we can say that ,when r is more then the speed will be minimum and when r is low then speed will be maximum.
