6. Calculate the mass of mass A in the diagram. The frame joining the masses is massless.
A
centre of mass
15 cm
30 cm
15 cm
3 kg
8 kg
40 cm
Figure 4.36​

Which of the following explains why it took so long for the public to accept the negative health effects of smoking? a)people were waiting for counter reasons, and those were presented.b)scientists had not completely finalized their results, which took 30 years.c)cigarettes were cheaply available and media channels were very inefficient.d)cigarette manufacturers were trying hard to bring an alternative into the market

A2000 kg car is rounding a curve of radius 200 m on a level road. the maximum frictional force the road can exert on the tires of the car is 4000 n. what is the highest speed at which the car can round the curve?

J. j. thomson’s experiment disproved the theory that an atom