- A bullet is shot vertically upward and rises for a maximum height of 1000 m. What is the initial velocity...
A bullet is shot vertically upward and rises for a maximum height of 1000m. What is the initial velocity of the bullet and the total time of flight?
Date posted: January 14, 2019.
- Explain what is meant by electromagnetism and give examples of its applications.(Solved)
Explain what is meant by electromagnetism and give examples of its applications.
Date posted: January 5, 2019. Answers (1)
- State Newton's three Laws of Motion.(Solved)
State Newton's three Laws of Motion.
Date posted: January 5, 2019. Answers (1)
- Explain why during anomalous expansion of water, heat transfer is limited to conduction and radiation(Solved)
Explain why during anomalous expansion of water, heat transfer is limited to conduction and radiation.
Date posted: December 30, 2018. Answers (1)
- How much heat is taken per second by the ice which melts if the steam jet were replaced by an electric heater in...
How much heat is taken per second by the ice which melts if the steam jet were replaced by an electric heater in the ice and connected to a 240V supply, what current would be needed to give the same heat per second to the apparatus?
Date posted: December 28, 2018.
- State a reason why it may not be possible to suck a liquid into your mouth using drinking straw on the surface of the moon(Solved)
State a reason why it may not be possible to suck a liquid into your mouth using drinking straw on the surface of the moon.
Date posted: December 10, 2018. Answers (1)
- State the reason why the speed of the water at the narrow section of a river is higher than at the wider section(Solved)
State the reason why the speed of the water at the narrow section of a river is higher than at the wider section.
Date posted: November 29, 2018. Answers (1)
- Explain how physics is an integral component of general education curriculum
Explain how physics is an integral component of general education curriculum.
Date posted: November 18, 2018.
- Two vertical opposite forces act on a metre rule at the 10cm and 60cm mark respectively. If each of the forces has a magnitude of 2.4N.calculate...(Solved)
Two vertical opposite forces act on a metre rule at the 10 cm and 60 cm mark respectively.if each of the forces has a magnitude of 2.4N. Calculate their moments on the metre rule about the 30 cm mark.
Date posted: November 13, 2018. Answers (1)
- Explain the applications of junction diodes(Solved)
Explain the applications of junction diodes.
Date posted: October 18, 2018. Answers (1)
- Explain the occurrence of forward bias of a p-n junction and reverse bias of a p-n junction(Solved)
Explain the occurrence of forward bias of a p-n junction and reverse bias of a p-n junction.
Date posted: October 18, 2018. Answers (1)
- What are junction diodes?(Solved)
What are junction diodes?
Date posted: October 18, 2018. Answers (1)
- What is an intrinsic semiconductor?(Solved)
What is an intrinsic semiconductor?
Date posted: October 18, 2018. Answers (1)
- Define the following terms (i) Conductors (ii) Insulators (iii) Semiconductors (Solved)
Define the following terms (i) Conductors (ii) Insulators (iii) Semiconductors
Date posted: October 18, 2018. Answers (1)
- Hazards of radioactivity and their precautions(Solved)
Hazards of radioactivity and their precautions
Date posted: October 17, 2018. Answers (1)
- A radioactive element has an initial count rate of 2,400 counts per minute on a scaler. The count rate falls to 300 units per minute...(Solved)
A radioactive element has an initial count rate of 2,400 counts per minute on a scaler. The count rate falls to 300 units per minute in 30 hours, (a) Calculate the half-life of the element (b) If the initial number of atoms in another sample of the same element is 6.0 × 1020, how many atoms will have decayed in 50 hours?
Date posted: October 17, 2018. Answers (1)
- The initial number of atoms in a sample is 5.12 × 1020. If the half-life of the sample is 3.0 seconds, determine the number of...(Solved)
The initial number of atoms in a sample is 5.12 × 1020. If the half-life of the sample is 3.0 seconds, determine the number of atoms that will have decayed after six seconds.
Date posted: October 17, 2018. Answers (1)
- An isotope has a half-life of 576 hours. Complete the following table and show how mass varies with time from an initial mass of 1280...(Solved)
An isotope has a half-life of 576 hours. Complete the following table and show how mass varies with time from an initial mass of 1280 g?
Time (hrs)----576--1152--1728---2304
Mass (g)-------640--x------y-----z
Date posted: October 17, 2018. Answers (1)
- The half-life of a sample of a radioactive substance is 98 minutes. How long does it take for the activity of the sample to reduce...(Solved)
The half-life of a sample of a radioactive substance is 98 minutes. How long does it take for the activity of the sample to reduce to 1/16th of the original value?
Date posted: October 17, 2018. Answers (1)
- State the law of radioactive decay(Solved)
State the law of radioactive decay
Date posted: October 17, 2018. Answers (1)
- Explain ways of detecting nuclear radiation(Solved)
Explain ways of detecting nuclear radiation.
Date posted: October 17, 2018. Answers (1)
- Properties of radioactive emissions(Solved)
Properties of radioactive emissions
Date posted: October 17, 2018. Answers (1)
- Sodium has a work function of 2.0 e: Calculate (a) The maximum energy and velocity of the emitted electrons when sodium is Illuminated by...(Solved)
Sodium has a work function of 2.0 e: Calculate
(a) The maximum energy and velocity of the emitted electrons when sodium is Illuminated by a radiation of wavelength 150 nm.
(b) Determine the least frequency of radiation by which electrons are emitted. (Take ‘h’ = 6.626 × 10-34 Js, e = 1.6 × 10-19, c = 3.0 × 108 m/s and mass of electron = 9.1 × 10-31 kg).
Date posted: October 17, 2018. Answers (1)
- The threshold frequency for lithium is 5.5 × 1014 Hz. Calculate the work function for lithium. (Take ‘h’ = 6.626 × 10-34 Js)(Solved)
The threshold frequency for lithium is 5.5 × 1014 Hz. Calculate the work function for lithium. (Take ‘h’ = 6.626 × 10-34 Js)
Date posted: October 17, 2018. Answers (1)
- The work function of tungsten is 4.52 e V. Find the cut-off potential for photoelectrons when a tungsten surface is illuminated with radiation of wavelength...(Solved)
The work function of tungsten is 4.52 e V. Find the cut-off potential for photoelectrons when a tungsten surface is illuminated with radiation of wavelength 2.50 × 10-7 m. (Planck’s constant, h = 6.62 × 10-34 Js).
Date posted: October 17, 2018. Answers (1)
- The cut-off wavelength for a certain material is 3.310 × 10-7 m. What is the cut-off frequency for the material?(Solved)
The cut-off wavelength for a certain material is 3.310 × 10-7 m. What is the cut-off frequency for the material?
Date posted: October 17, 2018. Answers (1)
- What is Einstein’s photoelectric equation?(Solved)
What is Einstein’s photoelectric equation?
Date posted: October 17, 2018. Answers (1)
- Dangers of X-rays and the precautions(Solved)
Dangers of X-rays and the precautions.
Date posted: October 16, 2018. Answers (1)
- An x-ray tube operates at 60 kV and the current through it is 4.0 mA. Calculate the, (a) Number of electrons striking the target per...(Solved)
An x-ray tube operates at 60 kV and the current through it is 4.0 mA. Calculate the, (a) Number of electrons striking the target per second. (b) Speed of the electrons when they hit the target.
Date posted: October 16, 2018. Answers (1)
- Determine the energy possessed by X-rays whose frequency is 4 × 1017 Hz. (Solved)
Determine the energy possessed by X-rays whose frequency is 4 × 1017 Hz.
Date posted: October 16, 2018. Answers (1)