As per the question the mass of the boy is 50 kg.
The boy sits on a chair.
We are asked to calculate the force exerted by the boy on the chair at sea level.
The force exerted by boy on the chair while sitting on it is nothing else except the force of gravity of earth i.e the weight of the body .The direction of that force is vertically downward.
At sea level the acceleration due to gravity g = 9.8 m/s^2
Hence the weight of the boy 
[m is the mass of the body]
we have m = 50 kg.
Hence w = 50 kg ×9.8 m/s^2
=490 N kg m/s^2
= 490 N
Here newton [N] is the unit of force.
If we pull an object vertically upwards then we need to apply a force which is equal in the magnitude of the weight of the object
now when we pull the same object upwards along an inclined plane with angle then we require a force which will balance the component of weight along the inclined
so it is given as
so as if we compare the two forces we can say that since the value of sine is always less than 1 for an angle less than 90 degree
so in the 2nd case when we pull the object along the inclined plane it will require less effort
so correct answer is
<em>A. reduce effort</em>
The answer is C I just took this quiz.
Answer:
2
Explanation:
Sedimentary rocks are formed when sediment is deposited out of air, ice, wind, gravity, or water flows carrying the particles in suspension. This sediment is often formed when weathering and erosion break down a rock into loose material in a source area.
<h3><u>Answer;</u></h3>
Transmission
<h3><u>Explanation;</u></h3>
- <em><u>Light waves are types of waves that are electromagnetic waves, meaning they do not require material medium for transmission. </u></em>Light is transmitted as a transverse wave such that the vibration of particles is perpendicular to the direction of wave motion.
- <em><u>A material medium enables the transmission of a wave by the vibration of particles, atoms or molecules. </u></em>The vibration of particles in a medium helps in the transmission of a wave such that energy is transferred from one point to another due to the disturbance caused by the wave.
