Answer:
Explanation:
reading of scale = reaction force of surface R
centripetal force = R - mg = m v² / R , m is mass , v is velocity and R is radius of the circular path .
R = mg + m v² / R
given ,
m v² / R = .80 mg
v² = .80 x g x R
= .8 x 9.8 x 9 = 70.56
v = 8.4 m /s
T = ?
v1 = 0mph
v2 = 60mph
a = 8.7mph/s

Therefore, it takes 6.90 seconds for Jill to accelerate from 0 to 60 miles per hour.
Answer:
Because the angle of the sun moves/rotates in the summer, the sun's rays move their angle and impact the earth.
Answer:
Separation increases at all times that rock X falls because it falls with a greater speed
Explanation:
For both rocks, let initial velocity ∪=0
To find the displacement at any given time interval of Δt then
S= ∪Δt +0.5gΔt²
Since rock X is first released followed by Y, then X has a greater speed than Y therefore the distance covered by X is longer. This is because despite 0.5gΔt² being same for both rocks at any time Δt but rock X having already attained some velocity, its ∪Δt is more hence the separation S increases. Conclusively, S increases at all times that rock X falls since rock X falls with a greater velocity than rock Y