When an object is falling and reaches a constant velocity, the net force on the object is <em>zero</em> (it's not accelerating), and the weight of the object is equal to <em>the force of air resistance against the object</em>. (choice-D)
Answer: Nitrogen
Explanation: Nitrogen makes up 78% of the atmosphere, Oxygen makes up 21%, and Argon 0.9%.
Water vaper makes up between 1-4%, depending on the region.
Carbon Dioxide makes up only about 0.04%.
Humans rely on photosynthesis to generate food as well as provide energy for heating, lighting, and electricity.
Answer:
Explanation:
For free body diagram see attached sheet .
W is weight of steel girder acting at the middle point of its length . T is tension in the cable .
OB = √ ( 12² - 2² )
= 11.83 m .
OC = 11.83 / 2 = 5.915 m
Taking moment of tension T and weight W about point O
W x OC = T x OB
22 x 5.915 = T x 11.83
T = 22 x 5.915 / 11.83
= 11 kN
Considering forces acting in vertical direction and equating forces in opposite direction
T + R = W
R = W - T
= 22 - 11 = 11 KN
So force of grinder on the ground = R
= 11 KN.