Answer:
Work done, W = 6 J
Explanation:
It is given that,
Force of gravity acting on the book, weight of the book is 15 N
We need to find the work done in lifting the book straight up for a distance of 0.4 meters.
The weight of the book is acting in downward direction and the book is lifted straight up, it means angle between them is 180 degrees. Work done is given by :

So, the magnitude of work done in lifting the book is 6 joules.
Answer:
1. 
2. 
Explanation:
1. According to Newton's law of motion, the puck motion is affected by the acceleration, which is generated by the push force F.
In Newton's 2nd law: F = ma
where m is the mass of the object and a is the resulted acceleration. So in the 2nd experiment, if we double the mass, a would be reduced by half.

Since the puck start from rest, in the 1st experiment, to achieve speed of v it would take t time

Now that acceleration is halved:


You would need to push for twice amount of time 
2. The distance traveled by the puck is as the following equation:

So if the acceleration is halved while maintaining the same d:

As
, then
. Also 



So t increased by 1.14
Answer:
The answer is C. Abundant natural resources
Explanation:
A is wrong because humans cause pollution, B is wrong because we use natural resources and their supply would deteriorate, and D is wrong because we already break down rainforests and they are getting smaller.
Is D) Zeroes and One's :))))
Answer:
As rocket mass increases, acceleration decreases.
Explanation:
From Newton's second law of motion;
F= ma
Where;
m= mass of the object
a= acceleration of the object
Hence we can write;
a= F/m
This implies that an increase in mass (m) will lead to a decrease in acceleration if the force on the object is held constant.
Hence, if the rockets have different masses, they will have different accelerations.