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.
1 astronomical unit 1 AU = 1.4960 * 10^11 meters
it is the average distance between earth and sun
mercury to sun distance is = 46,000,000 * 1000 meters
= 4.6 * 10^9 meters = 4.6 * 10^9 / 1.4960 * 10^11 AU
= 3.0.74 / 100 = 0.0374 AU
River shore is located at distance
speed of the woman is given as
now the time taken by the woman to cover the distance is
for the same time interval the dog will run to and fro with speed 4.5 m/s
so the total distance moved by the dog is given by
<em>so the total distance that dog will move is 7200 m or 7.2 km</em>
Answer:
The linear velocity is 
Explanation:
According to the law of conservation of energy
The potential energy possessed by the hoop at the top of the inclined plane is converted to the kinetic energy at the foot of the inclined plane
The kinetic energy can be mathematically represented as
Where 
is the moment of inertia possessed by the hoop which is mathematically represented as
Here R is the radius of the hoop
is the angular velocity which the hoop has at the bottom of the lower part of the inclined plane which is mathematically represented as
Where v linear speed of the hoop's center of mass just as the hoop leaves the incline and rolls onto a horizontal surface
Now expressing the above statement mathematically
=> 
=> 
=> 
=> 
Substituting values
