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Physics
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Explain why excited atoms only emit certain frequencies of radiation after an electron collides with the atom

  1. Radiation is emitted via photons2) Photon energy is governed by the equation E = hc/wavelength, where h = the Planck constant and c = the speed of light. Both h and c are constants3) Electrons have ...
MH
Answered by Michael H. Physics tutor
5847 Views

I do 400J of work compressing a gas, but I maintain the same temperature. What is the delta U, Q and W in this case?

U = 0Q = -400W = -400

HC
Answered by Helen C. Physics tutor
2269 Views

A trolley of mass 0.75kg is running along a frictionless track at a constant speed of 0.7ms-1, as the trolley passes below a mass of 0.5kg the mass drops a short vertical distance onto the trolley. Calculate the new velocity of the trolley and mass.

Momentum = mass x velocityInitial momentum = 0.75 x 0.7 =0.525kgms-1Momentum is assumed conserved so final momentum = 0.525kgms-1So final mass = 0.5+0.75 = 1.25kgSo final velocity = 0.525/1.25Final veloci...

AM
Answered by Alexander M. Physics tutor
2321 Views

A person has a suitcase with wheels. The person pulls the suitcase with a horizontal force of 13 N for 110 m. Calculate the work done on the suitcase by the person (3 marks).

Work done = force x distance moved

Work done = 13 N x 110 m

Work done = 1430 J

JT
Answered by Jasmine T. Physics tutor
4893 Views

What velocity should your boat have if you want to cross a 72m wide river in 6s by the shortest distance, with a 5 m/s downstream current?

Key physics concepts: Velocity vectors, Distance/speed/time relations Key mathematical concepts: Trigonometry, Pythagorean triples, Vector addition/subtraction.Recall that velocity is a vector

Answered by Physics tutor
1956 Views

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