Answer:
x_total = 600 m
Explanation:
This is an exercise and kinematics, let's find the time it takes to reach the velocity 20 m / s
v = v₀ + a t
as part of rest v₀ = 0
t = v / a
t = 20/2
t = 10 s
let's find the distance traveled in this time
x₁ = vo t + ½ a t2
x₁ = 0 + ½ 2 10²
x₁ = 100 m
The remaining time is
t₂ = 35 - t
t₂ = 35 - 10
t₂ = 25 s
as in this range it has a constant speed
v = x₂ / t₂
x₂ = v t₂
x₂ = 20 25
x₂ = 500 m
the total distance traveled is
x_total = x₁ + x₂
x_total = 100 + 500
x_total = 600 m
We don't know the change in velocity, so can't answer.
Explanation:
For each object, the initial potential energy is converted to rotational energy and translational energy:
PE = RE + KE
mgh = ½ Iω² + ½ mv²
For the marble (a solid sphere), I = ⅖ mr².
For the basketball (a hollow sphere), I = ⅔ mr².
For the manhole cover (a solid cylinder), I = ½ mr².
For the wedding ring (a hollow cylinder), I = mr².
If we say k is the coefficient in each case:
mgh = ½ (kmr²) ω² + ½ mv²
For rolling without slipping, ωr = v:
mgh = ½ kmv² + ½ mv²
gh = ½ kv² + ½ v²
2gh = (k + 1) v²
v² = 2gh / (k + 1)
The smaller the value of k, the higher the velocity. Therefore:
marble > manhole cover > basketball > wedding ring
Answer:
Answered
Explanation:
The radius of curvature of the mirror R = 20 cm
then the focal length f = R/2 = 10 cm
(a) From mirror formula
1/f = 1/di + /1do
then the image distance
di = fd_o / d_o - f
= (10)(40) / 40-10
= 30.76 cm
since the image distance is positive so the image is real
ii) when the object distance d_0=20 cm
di = 10×20/ 20-10
= 20
Hence, the image must be real
iii)when the object distance d_0 = 10
di = 10×10 / 10-10 = ∞ (infinite)
the image will be formed at ∞
here also image will be real but diminished.
