Answer:
51,882 J
Explanation:
In order to convert the heat from calories to joule, we must remember the conversion factor:
1 cal = 4.184 J
Keeping in mind this, we can set up a proportion to find how much Joules correspond to 12,400 calories:
Newton's first law of motion is connected with inertia :)
Answer:
Option (a)
Explanation:
We will discard options that don't fit the situation:
Option b: <em>Incorrect </em>since if the driver "hits the gas" then velocity is augmenting and it's not constant.
Option c and d: <em>Incorrect </em>since the situation doesn't give us any information that could be related directly to the terrain or movement direction.
Option a: Correct. At <em>stage 1</em> we can assume the driver was going at constant speed which means acceleration is constantly zero. At <em>stage 2 </em>we can assume the driver augmented speed linearly, this is, with constant positive acceleration. At <em>stage 3 </em>we can assume the driver slowed the speed linearly, with constant negative acceleration.
Answer:
<h2>B. 20°</h2>
Explanation:
Range in projectile is defined as the distance covered in the horizontal direction. It is expressed as R = U²sin2Ф/g
U is the initial velocity of the body (in m/s)
Ф is the angle of projection
g is the acceleration due to gravity.
Given U = 14m/s, g = 9.8m/s and range R = 15 m
we will substitute this value into the formula to get the projection angle Ф as shown;
15 = 15²sin2Ф/9.8
15*9.8 = 15²sin2Ф
147 = 225sin2Ф
sin2Ф = 147/225
sin2Ф = 0.6533
2Ф = sin⁻¹0.6533
2Ф = 40.79°
Ф = 40.79°/2
Ф = 20.39° ≈ 20°
Hence, the range is greatest at angle 20°
Answer:
Total heat transfer is positive
Total work transfer is positive
Explanation:
The first law of thermodynamics states that when a system interacts with its surrounding, the amount of energy gained by the system must be equal to the amount of energy lost by the surrounding. In a closed system, exchange of energy with the surrounding can be done through heat and work transfer.
Heat transfer to a system is positive and that transferred from the system is negative.
Also, work done by a system is positive while the work done on the system is negative.
Therefore, from the question, since the heat engine inputs 10kJ of heat, then heat is being transferred to the system. Hence, the sign of the total heat transfer is positive (+ve)
Also, since the heat engine outputs 5kJ of work, it implies that work is being done by the system. Hence the sign of the total work transfer is also positive (+ve).
