Recent content by ntcctnntcctn

The solution: The symbol of degree is omitted. AD=BC (given) BE=DC (given) angleACD=180-angleBAC-angleADC (angle sum of triangle) =180-35-110 =35 Because angleACD=angleBAC Therefore DA=DC (sides opp. eq. angle) angleCDB=angleACD+angleCAD (ext. angle of...

It is a physics question. At least it is in the Hong Kong Certificate of Education Examintion, under the topic heat. It is a physical change because no new substance is formed. I think it is enough to post the solution as it should be very simple. E=energy, m=mass, c=specific heat capacity...

I think the answer of the book is https://www.physicsforums.com/attachment.php?attachmentid=4709&stc=1 AB=10, AC=3, Angle BAC=115 degree BC^2=10^2+3^2-2*10*3*cos115 BC=11.6, cor. to 3 sig. fig. But I do not know whether it is correct. :frown:

Remember, energy gained by the water + energy gained by the copper vessel =energy lost by the copper lump and E=mc△t , which m=mass, c= specific heat capacity , △t=change in temperature , E=energy

Let me summarize the solution. a=acceleration u=initial velocity v=final velocity s=displacement t=time taken a=(v-u)/t a=(17.0-8.0)/3.0 a=3 m/(s^2) s=((u+v)*t)/2 s=((8.0+17.0)*3.0)/2 s=37.5 m Therefore, the acceleration is 3 m/(s^2) to his original direction and the...