Answer:
When the object in creases or decreases in temperature.
Explanation:
Heat flow moves energy from a higher temperature to a lower temperature. The bigger the difference in temperature between two objects, the faster heat flows between them. When temperatures are the same there is no change in energy due to heat flow. Radiation and Conduction are the two methods of heat transfer..
Answer:
Explanation:
Electron's kinetic energy = 2 eV
= 2 x 1.6 x 10⁻¹⁹ J
1/2 m v² = 3.2 x 10⁻¹⁹
1/2 x 9.1 x 10⁻³¹ x v² = 3.2 x 10⁻¹⁹
v² = .703 x 10¹²
v = .8385 x 10⁶ m/s
Electrons revolve in a circular orbit when forced to travel in a magnetic field whose radius can be expressed as follows
r = mv / Bq
where m , v and q are mass , velocity and charge of electron .
here given magnetic field B = 90 mT
= 90 x 10⁻³ T
Putting these values in the expression above
r = mv / Bq
= 
= .052 mm.
Answer:
False
Explanation:
As we know that, the Balmer series gives the n values as,
.
.
Now the value of wavelength can be calculated as,
.
Here,
.
And
.
Now,
.
Therefore,

Therefore, the wavelength of Balmer series lies in visible region which is 547 nm.
The percentage error in his experimental value is -51.97%.
<h3>What is percentage error?</h3>
This is the ratio of the error to the actual measurement, expressed in percentage.
To calculate the percentage error of the student, we use the formula below.
Formula:
- Error(%) = (calculated value-accepted value)100/(accepted............. Equation 1
From the question,
Given:
- Calculated value = 4.15 g/cm
- accepted value = 8.64 g/cm
Substitute these values into equation 1
- Error(%) = (4.15-8.64)100/8.64
- Error(%) = -4.49(100)/8.64
- Error(%) = -449/8.64
- Error(%) = -51.97 %
Hence, The percentage error in his experimental value is -51.97%.
Learn more percentage error here: brainly.com/question/5493941