Answer:
The positive velocity occurs the instant the coin leaves our hand. It immediately begins slowing up until its upward velocity becomes zero at the maximum height.
Explanation:
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<u>Answer:</u>
<em>A water strider can walk along the surface of earth due to the surface tension of water.
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<u>Explanation:</u>
Fluids have a <em>tendency to shrink to minimum possible surface area</em> and this is called surface tension. It usually occurs due to the greater force of cohesion between molecules of same substance when compared to adhesive force between molecules of different substances. Objects with greater densities can float along water surface due to the <em>role played by surface tension.
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When insects walk along the water surface they are pulled down due to gravity. But the force of attraction between the legs of the insect and water molecules is minimal. Thus the surface tension would always tend to maintain the <em>flatness of water overcoming</em> the push by the legs of the strider.
When the insect’s weight pulls it down , the surface tension pushes it upwards overcoming this force of gravity. This is how<em> water striders move along the surface of water. </em>
Gravity on the surface = 4 m/s^2
Now, the acceleration due to centripetal motion, a = v^2/R
Where,
v= 10^3 m/s, R = 10^6 m
Then,
a = (10^3)^2/(10^6) = 1 m^2/s
The net gravitational acceleration = 4-1 = 3 m/s^2
The reading on the spring scale = ma = 40*3 = 120 N
Answer: is A
The acceleration of an object is determined by its mass and the net force acting on it.
Newton's second law says that "F=ma". what this means is that the force you apply to an object is equal to its mass times how fast it is accelerating.
Hope it helped.
It transfers and changes into different types of energy, this is why the ground feels hot when something moves fast over it.