ive science已知中文問題,求答案+解釋(最好用中文)

1. A ball is thrown into outer space(no). According to Newton's First Law,
(a)the ball will fly off along a straight line
(b)the ball will fly off in a circular path
(c)the ball will stay on a straight line path at a constant speed
(d)the ball will stay on a straight line path and under acceleration

2. A car runs at a constant velocity on the road still needs to burn petrol to keep it running at that velocity. Otherwise it will slow down
gradually and come to a stop. Why?
(a)Newton's First Law is wrong
(b)Newton's First Law does not apply in this case
(c)Petrol is used to generate power to overcome friction. Then th enet force acting on the car may be zero
(d)Petrol is used to keep the car warm

3. A person standing on the ground on earth will have an acceleration equal to g due to his own weight. Why are we not feeling this
acceleration at all?
(a)The normal reaction of the ground has balanced the weight. Net force on the person is zero and no acceleration is resulted
(b)Friction of the air has prevented us from being acceleration. Net force on the person is zero and no acceleration is resulted
(c)Air upthrust(浮力) has balanced the weight. Net force on the person is zero and no acceleration is resulted
(d)We are used to this acceleration

4. In an experiment, a stone and a feather are dropped from the top of a wall at the same time
(a)The stone will reach the ground first
(b)The feather will reach the ground first
(c)Both will reach the ground at the same time
(d)In the morning the stone reaches the ground first. In the afternoon the feather reaches the ground first

5. Two rocks, one with mass 10 kg and the second 20 kg, are dropped at the same time from the top of a wall. Assuming no friction
from air, no wind ect.,then
(a)The 20 kg rock will reach the ground first
(b)The 10 kg rock will reach the ground first
(c)Both will reach the ground at the same time
(d)The heavier stone will reach the ground first