D. A body at rest tends to remain at rest. 6. Quantum mechanics is necessary to describe the behavior of the following objects, except A nucleus of a heavy metal atom. B. diatomic oxygen (two bound oxygen atoms). C. a chunk of ice traveling at a significant fraction of light speed D. electrons orbiting a helium nucleus. 7. A force of 40 N accelerates a given mass by 20 m/s2. If the mass is doubled and the force is halved, what will be the new acceleration? F=ma (Ask for help on this one) A. 5 m/s2 B. 10 m/s2 C. 20 m/s2 D. 80 m/s2 S. A boy shoves a 2.0-kg brick on the ground with his foot. He applies a constant force of 10.0 N. Meanwhile, friction with the ground opposes the motion with 11L 9 E-m​

Aplane flies a distance d from west to east at a constant speed vp , with respect to the air in a time twe . on the return trip, the plane flies a distance d from east to west at a constant speed vp , with respect to the air in a time tew . on both trips the wind blows from west to east at a constant speed va , with respect to the ground 1) what is tew in terms of vp, va, and d, as needed? tew=dvp tew=dvp+va tew=dva tew=dvpâ’va tew=12dvp tew=12dvp+va tew=12dvpâ’va your submissions: b submitted: saturday, january 26 at 6: 49 pm feedback: feedback will be given once all questions have been attempted and the grade cluster button has been pressed. 2) what is twe in terms of vp, va, and d, as needed? twe=dvp twe=dvp+va twe=dva twe=dvpâ’va twe=12dvp twe=12dvp+va twe=12dvpâ’va your submissions: d submitted: saturday, january 26 at 6: 49 pm feedback: feedback will be given once all questions have been attempted and the grade cluster button has been pressed. 3) assuming d = 2300 miles, vp = 400 miles/hr, and twe = 4 hours, what is va, the speed of the wind with respect to the ground? va = 100 miles/hr va = 575 miles/hr va = 200 miles/hr va = 175 miles/hr va = 975 miles/hr 4) once again, assuming d = 2300 miles, vp = 400 miles/hr, and twe = 4 hours, what is tew, the time it takes the plane to fly a distance d miles from east to west? tew = 5.75 hours tew = 11.5 hours tew = 7.67 hours tew = 8 hours tew = 10.2 hours

You are standing on a boat. which of the following strategies will make the boat start moving? a. pushing the mast b. throwing some cargo out of the boat c. pushing the front ofthe boat d. pushing another passenger

Lacie kicks a football from ground level at a velocity of 13.9 m/s and at an angle of 25.0° to the ground. how long will the ball be in the air before it lands? round your answer to the nearest tenth. s how far will the football travel before it lands? round your answer to the nearest tenth. m