D
Giddy UP!!!!!!!!!!!!!!!!!!!!!
Answer:
A) When the angle between the Force (F) and Displacement (x) is 0°, because, Work done (W) is directly proportional to the Cosine of the Angle between the Force applied and the resultant displacement of the subject.
W = F•x cos ∅
If ∅ = 0°,
W = F•x ===> Maximum Work Done.
If ∅ = 45°,
W = F•x/√2
If ∅ = 90°,
W = 0
If ∅ = 180°,
W = –F•x ===> Minimum Work Done.
Answer:
A) The acceleration is zero
<em>B) The total distance is 112 m</em>
Explanation:
<u>Velocity vs Time Graph</u>
It shows the behavior of the velocity as time increases. If the velocity increases, then the acceleration is positive, if the velocity decreases, the acceleration is negative, and if the velocity is constant, then the acceleration is zero.
The graph shows a horizontal line between points A and B. It means the velocity didn't change in that interval. Thus the acceleration in that zone is zero.
A. To calculate the acceleration, we use the formula:

Let's pick the extremes of the region AB: (0,8) and (12,8). The acceleration is:

This confirms the previous conclusion.
B. The distance covered by the body can be calculated as the area behind the graph. Since the velocity behaves differently after t=12 s, we'll split the total area into a rectangle and a triangle.
Area of rectangle= base*height=12 s * 8 m/s = 96 m
Area of triangle= base*height/2 = 4 s * 8 m/s /2= 16 m
The total distance is: 96 m + 16 m = 112 m
The correct answer to the question is : D) 352.6 m/s.
CALCULATION :
As per the question, the temperature is increased from 30 degree celsius to 36 degree celsius.
We are asked to calculate the velocity of sound at 36 degree celsius.
Velocity of sound is dependent on temperature. More is the temperature, more is velocity of sound.
The velocity at this temperature is calculated as -
V = 331 + 0.6T m/s
= 331 + 0.6 × 36 m/s
= 331 + 21.6 m/s
= 352.6 m/s.
Here, T denotes the temperature of the surrounding.
Hence, velocity of the sound will be 352.6 m/s.