Hi can someone explain Q15,28,32,34,36 please? Thank you so much!
For Q15:
Resolve the 4 N force that is slanted and this is shown as red line arrows in the diagram.
When the respective red line arrows are translated horizontally and vertically to overlap the vertical 3 N force and horizontal 4 N force as shown as yellow line arrows in the diagram.
The non-overlap part in the horizontal and vertical direction is the components of the resultant force.
Hi can someone explain Q15,28,32,34,36 please? Thank you so much!
For Q32:
Since the wires are in series with the kettle, you can form an equation using V = IRtotal as the first equation. The power dissipated in the circuit is P = I2Rtotal and you use this equation to form the second equation. You have 2 unknowns with 2 equations, so you can solve the problem.
Since the wires are in series with the kettle, you can form an equation using V = IRtotal as the first equation. The power dissipated in the circuit is P = I2Rtotal and you use this equation to form the second equation. You have 2 unknowns with 2 equations, so you can solve
Hmmmmm... well the thing is I know what todo but IDK which value to sub in ..... What I did was I find the I=10A ... after that step then I m confuse.....
Hmmmmm... well the thing is I know what todo but IDK which value to sub in ..... What I did was I find the I=10A ... after that step then I m confuse.....
The current in the kettle is 10 A. Can you show how do you get the current as 10 A?
You can use Kirchhoff’s voltage rule to write an equation of the potential drop through the circuit to deduce the p.d. across the kettle.
Hmmmmm... well the thing is I know what todo but IDK which value to sub in ..... What I did was I find the I=10A ... after that step then I m confuse.....
An old-fashioned 60W lamp converts 95% of its energy supply into heat. A 4.0W modern lamp has the same power output of light as the old-fashioned lamp. What is the efficiency of the modern lamp? A 5.0% B 6.7% C 75% D 95%
An old-fashioned 60W lamp converts 95% of its energy supply into heat. A 4.0W modern lamp has the same power output of light as the old-fashioned lamp. What is the efficiency of the modern lamp? A 5.0% B 6.7% C 75% D 95%
ans c can explain ?
For the old-fashioned lamp, how much power is converted into the useful output? Say x useful power.
An old-fashioned 60W lamp converts 95% of its energy supply into heat. A 4.0W modern lamp has the same power output of light as the old-fashioned lamp. What is the efficiency of the modern lamp? A 5.0% B 6.7% C 75% D 95%
efficiency of 60W lamp is 5% as 95% is heat energy. So only 3W is power output. Therefore power output of 4W lamp is the same 3W as stated by question. 3/4 X100= 75%