Answer:
acceleration, a = 9.8 m/s²
Explanation:
'A ball is dropped from the top of a building' indicates that the initial velocity of the ball is zero.
u = 0 m/s
After 2 seconds, velocity of the ball is 19.6 m/s.
t = 2s, v = 19.6 m/s
Using
v = u + at
19.6 = 0 + 2a
a = 9.8 m/s²
To solve the problem it is necessary to use Newton's second law and statistical equilibrium equations.
According to Newton's second law we have to
where,
m= mass
g = gravitational acceleration
For the balance to break, there must be a mass M located at the right end.
We will define the mass m as the mass of the body, located in an equidistant center of the corners equal to 4m.
In this way, applying the static equilibrium equations, we have to sum up torques at point B,
Regarding the forces we have,
Re-arrange to find M,
Therefore the maximum additional mass you could place on the right hand end of the plank and have the plank still be at rest is 16.67Kg
Answer:
c. the location of Earth in its orbit.
Explanation:
It is known that the earth orbits the sun once every 365 days, during this time the<u> constellations that are visible in the sky are changing</u>.
This is due to the fact that depending on the position, we have access to different parts of the celestial tomb, that is, the stars and constellations visible from earth.
This is why Orion is visible in winter but not in summer, since in summer it is in a <u>different part of the orbit</u> and with visibility towards different constellations.
the answer is c. the location of Earth in its orbit.
Answer:
Efficiency of the machine = 75%
Explanation:
Given:
Input work = 8,000 J
Output work = 6,000 J
Find:
Efficiency of the machine
Computation:
Efficiency of the machine = [Output work / Input work]100
Efficiency of the machine = [6,000 / 8,000]100
Efficiency of the machine = 75%
Answer:
the armature and commutator
Explanation:
An electric generator converts mechanical energy to electrical energy. It is based on the principle that when a conducting coil rotates in the magnetic field, an electric current is generated.
The rotating part is known as Armature. Commutator is cylindrical in shape and connected to armature which rotates with it. It also connects the armature to the external circuit by brushes.
Slip rings are connected to armature coil to maintain an electrical contact with the brushes.
