70 FIRST YEAR COURSE IN GENERAL SCIENCE 



EXERCISES 



1. A force of 50 kg. is acting toward the west, and one of 75 kg. 

 toward the east. What is the resultant force and what is the direc- 

 tion of motion? 



2. If the force of 50 kg. in Ex. 1 acted toward the east, what 

 would be the resultant force and the direction of motion? 



3. Represent a force of 100 Ib. acting east by a line 2 in. long, and 

 a force of 200 Ib. acting north by a line 4 in. long at right angles to the 

 first line. Draw with dotted lines two sides opposite and parallel to 

 these, making a four-sided figure. Draw the diagonal line between the 

 two force lines. That represents the resultant force. Measure it and 

 compute its value, if 1 in. represents a 50-pound force. State the 

 magnitude and direction of the resultant. 



4. Represent a force of 25 g. acting southeast and one of 50 g. acting 

 north. Draw the other two sides of the figure parallel to the first two. 

 Measure the diagonal between the force lines and compute its value. 

 Which force does it more nearly approach in direction? Why? 



6. A block of stone 30 x 25 x 100 cm. weighs 225 kg. (1 kg. equals 

 1,000 g.) Calculate its density. 



6. A block of wood of the dimensions given in Ex. 5 weighs 

 54,625 g. Calculate its density. 



7. The density of ice is .93 g. per cubic centimeter. What is its 

 specific gravity? If put into water, will it sink or float? Why? 



8. A rough piece of granite weighs in air 375 kg. In the water it 

 weighs 250 kg. What is its specific gravity? What is its volume? 

 From its specific gravity, determine the density. 



9. An irregular piece of brass weighs 5 Ib. 9 oz. in air; 4 Ib. 14 oz. 

 in water. Find its specific gravity. 



