Under what conditions is an object weightless? (Ignore effects of air resistance.)
A) when it is in free-fall
B) when it is on the Moon
C) when it is detached from Earth's surface (such as in an airplane)
D) when it is moving in at constant velocity
A) when it is in free-fall
You might also like to view...
A 4.0 kg mass has a velocity of 10 m/s to the EAST. The 4.0 kg mass undergoes an acceleration of 4.0 
to the WEST for 3.0 sec. What is the velocity of the 4.0 kg mass at the end of the 3.0 sec interval?
A. 22 m/s to the WEST B. 2.0 m/s to the WEST C. 0.0 m/s D. 2.0 m/s to the EAST E. 22 m/s to the EAST
A plane flies directly from city A to city B, which are separated by 2300 mi. From A to B, the plane flies into a 65 mi/h headwind. On the return trip from B to A, the wind velocity is unchanged
The trip from B to A takes less than the trip from A to B. What is the airspeed (assumed constant) of the plane relative to the air (that is, the airspeed)? A) 530 mi/h B) 610 mi/h C) 480 mi/h D) 400 mi/h
A bridge is made with segments of concrete 50 m long. If the linear expansion coefficient is 12 × 10^?6 (°C)?1, how much spacing (in cm) is needed to allow for expansion during an extreme temperature change of 150° F?
a. 10 b. 2.5 c. 7.5 d. 5.0 e. 9.5
Atoms are mostly empty space
What will be an ideal response?