8. A jogger runs northward in a straight line with an average velocity of 5.0 m/s for 4.0 min and then with an average velocity of 4.0 m/s for 3.0 min.
a) What is her average speed?

b) What is her average velocity?

The act of moving from one place to another. a. locomotor b. aerobic c. stationary d. static

Acarpenter is driving a 15.0-g steel nail into a board. his 1.00-kg hammer is moving at 8.50 m/s when it strikes the nail. half of the kinetic energy of the hammer is transformed into heat in the nail and does not flow out of the nail. what is the increase in temperature of the nail after the three blows that the carpenter needs to drive the nail in completely? the specific heat of steel is 448 j/kg ∙ k. a) 2.7 k b) 1.8 k c) 7.7 k d) 8.1 k e) 3.6 k

In the absence of friction gravity and all other external forces