Question

17) Determine the work, in J, required to stop a 1500-kg car traveling at 30 m/s. (hint: use the work-energy theorem).

a) 2.4 x 10⁵

b) 8.2 x 10⁵

c) 1.7 x 10⁵

d) 6.8 x 10⁵

Answer_______________

18) 10 J of heat are removed from a gas sample while it is being compressed by a piston that does 30 J of work. Determine, in J, the change in thermal energy of the system.

a) 4

b) 10

c) 20

d) 3

Answer_______________

19) It is possible for a device to transform a given amount of heat completely into work.

a) true

b) false

Answer_______________

20) The density of a block of iron is 7,860 kg/m³. The density of mercury is 13,950 kg/m³.      This block of iron will:

a) float in mercury

b) sink in mercury

c) hang motionless in mercury

d) none of the above

Answer_______________

Answer 1

17. Work = change in kinetic energy

W= .5*1500*30^2

W= 675000 j

Option d is correct