Which of the following is true about waves?
a) they always move matter
b) they are always visible
c) they carry energy
d( they can only travel though outer space

The percent efficiency of a machine can never be 100% (or greater), because in the real world some energy is always converted into a. heat b. work c. input force d. output force

Figure 9 on page 362 shows various motions of balls. the curved path followed by the yellow ball in b in picture b is result of a) inertia b) centripetal motion c) gravity and horizontal velocity d) linear motion

Describe uniform velocity and variable velocity in short