Answer:
<h2>154.73N</h2>
Explanation:
The question is incomplete. Here is the complete question.
Using the strap at an angle of 31° above the horizontal, a Grade 12 Physics student, tired from studying, is dragging his 15 kg school bag across the floor at a constant velocity. (a) If the force of tension in the strap is 51 N, what is the normal force.
Check the diagram related to the question in the attachment below for better understanding.
The normal force is the reaction acting perpendicular to the force of tension in the strap and opposite the weight of the bag. They are the forces acting along the vertical.
The normal force N will be the sum of the force of tension acting along the vertical (Ty) and the weight of the bag (W).
Ty = 15sin31°
Ty = 7.73N
W = mass * acceleration due to gravity
W = 15.0*9.8
W = 147N
The normal force is therefore expressed as;
N = Ty + W
N = 7.73 + 147
N = 154.73N
Water boiling, no cheamical bonds have been altered.
Answer:
The average power is calculated as 735.0 W
Solution:
As per the question:
Total mass, M = 1200 kg
Counter mass of the elevator, m = 950
Distance traveled by the elevator, d = 54 m
Time taken, t = 3 min = 180 s
Now,
To calculate the average power:
First, we find the force needed for lifting the weight:
Force, F = (M - m)g = 
Now, the work done by this force:
W = Fd = 
Average power is given as:

6x2=12m
6x18=108
12m+108
Simplified: m+9 bc 12/12 and 108/12
Answer : A. It decreases and then increases.
Explanation : Troposphere is the lowermost layer of atmosphere.
Stratosphere is next layer up to the troposphere. As the jet descends from stratosphere towards the troposphere, the temperature initially decreases and then at troposphere is roughly constant and then steadily increases.
So, option (A) is correct.