The study of the inorganic world.
Answer:
0J
Option: B
Explanation:
Work is done when something is moved by the force in the direction of the force. That is the force (e.g., the weight) and the direction the object moves must be aligned for work to be done. In this given condition, the direction is horizontal and the force is downward as its gravity force. That 90° between the two vectors.
The work function is W = m × g ×h × cosθ
Hence,
Work done = 7 × 9.8 × 1.5 × cos(90)
Work done = 0 (cos
= 0)
Work done = 0
Therefore work done is 0 J.
Answer:
Object D
Explanation:
Use Newton's Second Law to determine the acceleration that each object has.
The force applied in both cases is 50 N, but the mass for object C and object D is different.
Let's start with object C first:
- F = ma
- 50 N = 10 kg · a
- 50 = 10a
- 5 = a
The acceleration object C undergoes is 5 m/s².
Now let's calculate object D next:
- F = ma
- 50 N = 2 kg * a
- 50 = 2a
- 25 = a
The acceleration object D undergoes is 25 m/s².
Object D has greater acceleration because it has a smaller mass. The object with a smaller mass will accelerate more in order to satisfy Newton's 2nd Law.
TLDR: It will reach a maximum when the angle between the area vector and the magnetic field vector are perpendicular to one another.
This is an example that requires you to investigate the properties that occur in electric generators; for example, hydroelectric dams produce electricity by forcing a coil to rotate in the presence of a magnetic field, generating a current.
To solve this, we need to understand the principles of electromotive forces and Lenz’ Law; changing the magnetic field conditions around anything with this potential causes an induced current in the wire that resists this change. This principle is known as Lenz’ Law, and can be described using equations that are specific to certain situations. For this, we need the two that are useful here:
e = -N•dI/dt; dI = ABcos(theta)
where “e” describes the electromotive force, “N” describes the number of loops in the coil, “dI” describes the change in magnetic flux, “dt” describes the change in time, “A” describes the area vector of the coil (this points perpendicular to the loops, intersecting it in open space), “B” describes the magnetic field vector, and theta describes the angle between the area and mag vectors.
Because the number of loops remains constant and the speed of the coils rotation isn’t up for us to decide, the only thing that can increase or decrease the emf is the change in magnetic flux, represented by ABcos(theta). The magnetic field and the size of the loop are also constant, so all we can control is the angle between the two. To generate the largest emf, we need cos(theta) to be as large as possible. To do this, we can search a graph of cos(theta) for the highest point. This occurs when theta equals 90 degrees, or a right angle. Therefore, the electromotive potential will reach a maximum when the angle between the area vector and the magnetic field vector are perpendicular to one another.
Hope this helps!
