Two electrons are separated by one cm. What is the ratio of the electric force to the gravitational force between them? (me = 9. 11 ´ 10-31 kg, ke = 8. 99 ´ 109 N×m2 /C2 , G = 6. 67 ´ 10-11 N×m2 /kg2 , and e = 1. 6 ´ 10-19 C) a. 2. 3 ´ 102 b. 1. 3 ´ 1020 c. 3. 1 ´ 1022 d. 4. 2 ´ 1042.

The rigid beam is supported by the three suspender bars. bars ab and ef are made of aluminum and bar cd is made of steel. if each bar has a cross-sectional area of 450 mm2, determine the maximum value of p if the allowable stress is (σallow)st = 200 mpa for the steel and ( σallow)al = 150 mpa for the aluminum. est = 200 gpa and eal = 70 gpa.

An astronaut in space cannot use a scale or balance to weigh objects because there is no gravity. but she does have devices to measure distance and time accurately. she knows her own mass is 77.4 kg , but she is unsure of the mass of a large gas canister in the airless rocket. when this canister is approaching her at 3.50 m/s , she pushes against it, which slows it down to 1.30 m/s (but does not reverse it) and gives her a speed of 2.60 m/s . what is the mass of the canister?

When using the scientist method, which step comes last?