. A 5 kg box is traveling at 10 m/s just before it hits a pillow. It takes 2 s for the box to stop. What is the force of impact provided by the pillow?
A. 100 N
B. 25 N
C. 5N
D. 4N

The velocity of car is 80.0 miles per hour. what is the velocity of car in meters per second? (1 km -0.621 miles) m/s

A100-watt light bulb illuminates a solar cell. the electricity from the solar cell operates a water pump that delivers 1 watt of power. what is the efficiency of the system?

Asolid round steel rod 6.25 mm in diameter and 375 mm long is rigidly bonded to the end of solid square brass rod 25 mm on a side and 300 mm long. the geometric axes of the bare are along the same line. an axial tensile force of 5.4 kn is applied at the extreme ends of the assembly. for steel e = 200 gpa and for brass e = 90 gpa. determine the total elongation for the assembly.