Top answers

An electron of mass 9.11x10^(-31) is fired from an electron gun at 7x10^6 m/s. What size object will the electron need to interact with in order to diffract?

Momentum of electron=mv=6.377x10^ -24 kg m/s λ=h/mv=6.63x10 -34 /6.377x10 -24 =1.039...x10 -10 = 1x10 -10 m
JG
Answered by Jozefina G. • Physics tutor
3710 Views

Explain, using appropriate laws of motion, why the air exerts a force on the engine in the forward direction.

This question is taken from AQA 2016 question 1 part 2, http://filestore.aqa.org.uk/sample-papers-and-mark-schemes/2016/june/AQA-74071-QP-JUN16.PDF The force is acting on the air by the engine. By Newton's 2...
WL
Answered by William L. • Physics tutor
7307 Views

Describe the difference between reflection and refraction (assume the mediums have smooth surfaces)

Reflection: a wave hits a surface, and bounces back into the medium it was originaly in Refraction: a wave enters a medium with a different refractive index to the original medium it was travelling in, at an...
AB
Answered by Abigail B. • Physics tutor
2945 Views

What do you understand by simple harmonic motion?

Is the motion of a mass on a spring when it is subject to the linear elastic restoring force given by Hooke's Law. The motion is sinusoidal in time and demonstrates a single resonant frequency. There are dif...
AT
Answered by Aitor T. • Physics tutor
2682 Views

Two balls with the same kinetic energy have mass of ball a = m and ball b = 2m. What is the ratio of their momentums: a/b?

We know that both balls have the same kinetic energy, so we can write E ka = E kb We also know that kinetic energy is given by the equation E k = 1/2 (mv 2 ) and momentum, p, is p = mv where m is the mass an...
ZR
Answered by Zachary R. • Physics tutor
7688 Views