A uniform metre ruler, acted upon by three forces is balanced on a pivot as shown in Figure 1.23 A) Which one of the forces has no moment about the pivot? Explain your answer.

B)Calculate the moments of the other two forces about the pivot

C)Will the ruler turn? Explain.

The first law of thermodynamics states that heat added to a system is neither created nor destroyed but is transformed ⇒ as it changes into other forms of energy.

There are two-speed cameras, one in an are where the speed limit is 30 km/h and another where the speed limit is 50 km/h. in which will there be a smaller time interval between the photographs? explain your answer.

Which of the following changes will increase the capacitance of a parallel-plate capacitor? (there could be more than one correct choice.) a) increase the charge on the plates b) decrease the poten5al between the plates c) increase the potential between the plates d) introduce a dielectric material between the plates e) decrease the separation between the plates