Answer:
The increase in the internal energy = 350 J
Explanation:
Given that
Q= 275 J
W= - 125 J
W' = 50 J
W(net)= -125 + 50 = -75 J
Sign -
1.Heat rejected by system - negative
2.Heat gain by system - Positive
3.Work done by system = Positive
4.Work done on the system-Negative
Lets take change in the internal energy =ΔU
We know that
Q= ΔU + W(net)
275 = ΔU -75
ΔU= 275 + 75 J
ΔU=350 J
The increase in the internal energy = 350 J
A. Formula: F=ma or F/m=a
10,000N/1,267kg≈7.9m/
B. Formula: a=
and s=d/t
speed= 394.6/15
s=26.3m/s
a=
a=1.75m/
C. 7.9-1.75=difference of 6.15m/
D. The force that most likely caused this difference is friction forces
Given that,
Radius of track, r = 50 m
time , t = 9 s
velocity, v = ?
Distance covered by car in one lap around a track is equal to the circumference of the track.
C = 2 π r = 2 * 3.14 * 50
C = 314.159 m
Distance covered by car, s = 314.159 m
Velocity = distance/ time
V = 314.159 / 9
V = 34.9 m/s
The average velocity of car is 34.9 m/s.
Answer:
The time rate of change in air density during expiration is 0.01003kg/m³-s
Explanation:
Given that,
Lung total capacity V = 6000mL = 6 × 10⁻³m³
Air density p = 1.225kg/m³
diameter of the trachea is 18mm = 0.018m
Velocity v = 20cm/s = 0.20m/s
dv /dt = -100mL/s (volume rate decrease)
= 10⁻⁴m³/s
Area for trachea =

0 - p × Area for trachea =



⇒

ds/dt = 0.01003kg/m³-s
Thus, the time rate of change in air density during expiration is 0.01003kg/m³-s
The work done is the product between the intensity of the force applied F, the amount of the displacement d of the book and the cosine of the angle

between the direction of the force and the direction of the displacement:

In our problem, the student is lifting the book, so he is applying a force directed upward, and the book is moving upward, so F and d are parallel and therefore the angle is zero, so

Therefore, the work done is