Answer:
The top of the circle
Explanation:
At the top of the circle, there are two forces pulling the ball towards the center of the circle: weight and tension.
∑F = ma
mg + T = mv²/r
As v goes down, T also goes down, until it eventually reaches 0.
At the bottom of the circle, weight is pulling down, or away from the center of the circle. Sum of the forces:
∑F = ma
T − mg = mv²/r
As v goes down, T also goes down. However, even at v=0, T cannot be less than mg.
The desk is in equilbrium, so Newton's second law gives
∑ <em>F</em> (horizontal) = <em>p</em> - <em>f</em> = 0
∑ <em>F</em> (vertical) = <em>n</em> - <em>mg</em> = 0
==> <em>n</em> = <em>mg</em>
==> <em>p</em> = <em>f</em> = <em>µn</em> = <em>µmg</em> = 0.400 (80.0 kg) <em>g</em> = 313.6 N
The student pushes the desk 3.00 m, so she performs
<em>W</em> = (313.6 N) (3.00 m) = 940.8 Nm ≈ 941 J
of work.
Answer:0.642
Explanation:
Given
initially car is at rest i.e u=0
When car hits the truck it's velocity is 4.5 m/s
it hits the truck after 7 sec
Now average acceleration of car is =
average acceleration of car =
average acceleration of car=
average acceleration of car=
Taking Down hill as positive x axis
average acceleration of car=
Natural sources of light include our sun and other stars, where the source of energy is nuclear energy (recall that the moon does not produce light but merely reflects sunlight), lightning, where the source is electrical, and fire, where the energy source is chemical.
