Four satellites are in orbit around the Earth. The heights and the masses of the four satellites are given in the table. For which satellite is the gravitational pull of Earth the weakest? F=Gmm1/r2
Satellite
Mass (kg)
Orbit height (km)
А
mo
21
B
2m
c
3m
D
4m

A. Satellite A
B. Satellite B
C. Satellite C
D. Satellite D

Which explanation describes the forces involved for a person to walk down the sidewalk? a. the person's feet push backward on the sidewalk; the sidewalk pushes backward on the person. b. the person's feet push forward on the sidewalk; the sidewalk does not push on the person. c. the person's feet push backward on the sidewalk; the sidewalk pushes forward on the person. d. the person's feet push forward on the sidewalk; the sidewalk pushes forward on the person.

8.29 two streams containing pyridine and acetic acid at 25°c are mixed and fed into a heat exchanger. due to the heat-of-mixing effect, it is desired to reduce the temperature after mixing to 25°c using a stream of chilled ethylene glycol as indicated in the diagram. calculate the mass flow rate of ethylene glycol needed. the heat capacity of ethylene glycol at these conditions is approximately 2.8 kj/(kg k), and the enthalpy change of mixing (δmixh) is given below.

Four friends, a, b, c, and d are standing varying distances away from a speaker which is producing sound waves.