Answer:
The force on the book is 250N.
Step-by-step explanation:
Newton's second law states that the equation for the force is:

In which m is the mass, in kilograms, and a is the acceleration, in m/s². F is the force measured in N.
In this question:

So

The force on the book is 250N.
So he worked 30.5 hours, he just didn't write some of the hours down. To find the hours he didn't write down, you subtract 8+

+

from 30.5, which equals
Answer:
The answer is "sometimes"
Step-by-step explanation:
Answer:
x = 400 when y = 100
Step-by-step explanation:
This is a question in relation to direct variation.
y ∝ 
y = k 
Given that, y = 45, x = 81. Then;
45 = k 
45 = 9k
k = 
k = 5
Thus the relationship among the variables is;
y = 5 
If y = 100, then;
100 = 5 
= 
= 20
x = 
x = 400
Therefore, x = 400 when y = 100.
Given:
Number of white roses = 4
Number of red roses = 8
To find:
The ratio of the number of red roses to the number of white roses.
Solution:
Using the given information, the ratio of the number of red roses to the number of white roses is




Therefore, the required ratio is 2:1.