Assuming the woman starts at rest, she descends the slide with acceleration <em>a</em> such that
(20.3 m/s)² = 2 <em>a</em> (42.6 m) → <em>a</em> ≈ 4.84 m/s²
which points parallel to the slide.
The only forces acting on her, parallel to the slide, are
• the parallel component of her weight, <em>w</em> (//)
• friction, <em>f</em>, opposing her descent and pointing up the slide
Take the downward sliding direction to be positive. By Newton's second law, the net force in the parallel direction acting on the woman is
∑ <em>F</em> (//) = <em>w </em>(//) - <em>f</em> = <em>ma</em>
where <em>m</em> = 77.0 kg is the woman's mass.
Solve for <em>f</em> :
<em>mg</em> sin(42.3°) - <em>f</em> = <em>ma</em>
<em>f</em> = <em>m</em> (<em>g</em> sin(42.3°) - <em>a</em>)
<em>f</em> = (77.0 kg) ((9.80 m/s²) sin(42.3°) - 4.84 m/s²) ≈ 135 N
Compute the work <em>W</em> done by friction: multiply the magnitude of the friction by the length of the slide.
<em>W</em> = (135 N) (42.6 m) ≈ 5770 N•m = 5770 J
Answer:
Hooke's law, given by 
is denoted with a negative sign to regard that the direction of restoring force that occurs opposite in direction of the force that caused the displacement 
. F represents the force required to create a spring displacement of .
Explanation:
As with many things in physics, the negative sign represents direction. In this case, after a spring is displaced a distance of from equilibrium, the restoring force created by the spring will be in opposite direction of the force applied to move the spring there, represented by F.
Answer:
The change in momentum for the bug and the car will be equal, impulses will be equal in opposite directions and the bug will have a greater acceleration compared to the car, because it has a smaller mass.
Explanation:
Hope this helps..
Answer:
Option c
Explanation:
Soil tilth refers to the physical condition of the soil, particularly with regards to the suitability of the soil for the growth of crop.
The determinants of the tilth in the soil incorporates the arrangement and steadiness of aggregated particles of the soil, pace of water penetration, level of air circulation, dampness content and seepage.
Thus option C follows the definition of the soil tilth.
Answer:
The centripetal acceleration is 6.95 m/s²
Explanation:
Given;
angular displacement of the blade, θ = 90.08⁰
duration of motion of the blade, t = 0.4 s
radius of the circle moved by the blade, r = 0.45 m
The angular speed of the blade in radian is calculated as;
The centripetal acceleration is calculated as;
a = ω²r
a = (3.93)² x 0.45
a = 6.95 m/s²
