Answer:
The average drag force is 1.206 (-i) N
Explanation:
You have to apply the equations of<em> Impulse</em>:
I=FmedΔt
Where I and Fmed (the average force) are vectors.
The Impulse can also be expressed as the change in the <em>quantity of motion</em> (vector P)
I=P2-P1
P=mV (m is the mass and v is the velocity)
You can calculate the quantity of motion at the beggining and at the end of the given time:
Replace the mass in kg, dividing the mass by 1000 to convert it from g to kg.
P1=(0.179kg)(30.252m/s) i= 5.414 i kg.m/s
P2=0.179kg)(28.452m/s) i = 5.092 i kg. m/s
Where i is the unit vector in the x-direction.
Therefore:
I= 5.092 i - 5.414 i = -0.322 i
The average drag force is:
Fmed= I/Δt = -0.322 i/ 0.267s = -1.206 i N
Answer:
20 m
Explanation:
We'll begin by calculating the kinetic energy of the mass. This can be obtained as follow:
Mass (m) = 10 kg
Velocity (v) = 20 m/s
Kinetic energy (KE) =?
KE = ½mv²
KE = ½ × 10 × 20²
KE = 5 × 400
KE = 2000 J
Finally, we shall the height to which the mass must be located in order to have potential energy that is the same as the kinetic energy. This can be obtained as follow:
Mass (m) = 10 kg
Acceleration due to gravity (g) = 10 m/s²
Potential energy (PE) = Kinetic energy (KE) = 2000 J
Height (h) =..?
PE = mgh
2000 = 10 × 10 × h
2000 = 100 × h
Divide both side by 100
h = 2000 / 100
h = 20 m
Thus, the object must be located at a height of 20 m in order to have potential energy that is the same as the kinetic energy.
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

Therefore, the ball has a velocity of 4m/s.
I think the correct answer form the choices listed above is option C. <span>The transfer of energy from objects with higher temperatures to objects with lower temperatures is defined as gradient transfer. If there are difference in temperature from one point and another point, then a gradient is present and heat transfer will surely happen.</span>