2) One end of a light inextensible string is attached to a tool box of mass 2.5 kg which is lying on a horizontal table. The string passes
over a smooth pulley and is tied at the other end to a bag of mass
1.4 kg.

a) Draw a diagram showing the forces acting on the tool box.
1.4 kg

b) If the tool box is just on the point of sliding, find a value for u,
the coefficient of friction.

3) The coefficient of friction between a load of sand and the tray of a truck in which it carries is
0.8. At what angle to the horizontal does the truck tray have to be tilted before the sand starts
to slide out?

4) Blocks of masses m and M are connected by a light string.
The coefficient of friction between m and the table surface is
miu.

Determine the acceleration of the masses and tension in the
string if m = 4 kg. M = 5 kg and miu= 0.30.​

How many milliliters of water at 23 °c with a density of 1.00 g/ml must be mixed with 180 ml (about 6 oz) of coffee at 95 °c so that the resulting combination will have a temperature of 60 °c? assume that coffee and water have the same density and the same specific heat. how much will the temperature of a cup (180 g) of coffee at 95 °c be reduced when a 45 g silver spoon (specific heat 0.24 j/g °c) at 25 °c is placed in the coffee and the two are allowed to reach the same temperature? assume that the coffee has the same density and specific heat as water. a 45-g aluminum spoon (specific heat 0.88 j/g °c) at 24 °c is placed in 180 ml (180 g) of coffee at 85 °c and the temperature of the two become equal. (a) what is the final temperature when the two become equal? assume that coffee has the same specific heat as water. (b) the first time a student solved this problem she got an answer of 88 °c. explain why this is clearly an incorrect answer.