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What is Newtons third law of motion?

To every action, there is always an equal and opposite reaction.Force always occurs in pairs. Consider two bodies A and B, force on a body A by B is equal and opposite to the force on the body B by A.i.e,(Fo...
SB
Answered by Subin B. • Physics tutor
2295 Views

Calculate the threshold wavelength for a metal surface with work function of 6.2 eV.

threshold wavelength where photoelectrons have no energy, i.e. Work function = hc/wavelength.Rearrange for wavelength and substitute. Wavelength = 2*10^-7 m.
DP
Answered by Daniel P. • Physics tutor
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Calculate the root mean squared speed for 16g of oxygen gas at 50(deg Celsius) and explain why we use this instead of the average velocity of all the particles.

Root mean squared speed is given by v(rms) = (3kbT/m)^(0.5) = 501.68. Student should show how to calculate the mass of each particle (m = (0.016)/0.5(6.01x10^23)), convert degrees celsius into kelvin and und...
JW
Answered by Jonathan W. • Physics tutor
2213 Views

A car of mass m travelling with a velocity v comes to rest over a distance d in time t. The constant frictional force acting on the car while it is braking is found using:

Newton's Second Law: F=maa=v-u/tUsing SUVAT equations: v 2 = u 2 +2asv (final velocity)=0 u(inital velocity)= v s=d Rearranging gives: -v 2 =2ad a=-v 2 /2d Therefore F= -mv 2 /2dNegative sign suggests the ca...
GH
Answered by Ghafoor H. • Physics tutor
8494 Views

An electron is accelerated through a uniform electric field of strength, E= 20 [N/C]. Determine the speed after the the electron travels 0.5 m from rest.

E=F/Q. F= 20*(1.69 10^-19)=3.38 10^-18NF=ma m=9.11 10-31 kgTherefore, a = 3.71 * 10^12 m/s^2Since v^2= u^2 + 2as and s= 0.5m,Then v=1.93 10^6 m/s
LF
Answered by Luke F. • Physics tutor
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