Question

When you walk at an average speed of 4 m/s, is 5s you'll cover a distance of A) 20 m. B) 2 m. C) 15 m. D) 10 m. An archer shoots an arrow. Consider the action forcer to be the bowstring against the arrow. The reaction to this force is A) combined weight of the arrow and bowstring B) arrow's push against the bowstring. C) friction of the ground against the archer's feet. D) grip of the archer's hand on the bow. A push on a 1-kg brick accelerates it. Neglecting friction, equally accelerating a 10-kg brick requires A) one-tenth the amount of force. B) 10 times as much force. C) 100 times as much force. D) just as much force. E) none of the above A rock weighs 30 N on Earth and another rock weighs 30 N on the Moon. Which rock has the greater mass? A) the one on Earth B) the one on the Moon D) not enough information C) They have the same mass. D) not enough information. 25) You cannot exert a force on a wall A) unless you put your mind to it. B) if the wall resists. C) unless the wall simultaneously exerts the same amount of force on you. 26) The distance a freely falling object falls from rest in one-half second is A) 4 m. B) 2m. C) 6 m. D) none of the above Two tennis balls fall through the air from a tall building. One of them is filled with1ead pellets. The ball to reach the ground first is the A) regular ball. B) lead-fitted ball. C) same for both

Answer 1

20.correct option is (a), 4 m/s × 5s = 20 m

21. Correct option is b, its reaction force will be arrow's push.

22. Correct option is a, from newtons law, F = ma,

For 1 kg, a = F/1 and for 10 kg , a = F/10

23. Correct option is C, its reaction force will be air resistance

24. Correct option is b, as acceleration due to gravity at moon is one sixth of that on Earth.

25. Correct option is c

26.d, [ -g= d/t²] g= 9.81 ,t =0.5 s

27.c, same for both