V₀ = V₁ + 2ax
V₀ = final velocity which is 0 m/s
V₁ = initial velocity which is 20 m/s
x = distance which is 60-(0.5 x 20) =50m
this is because his reaction time is 0.5 sec so he traveled 10m before stepping on the break paddle.
a= (V₀-V₁) / 2x
= (0-20) / 2*50
= -0.2m/s
the negative is because it is a deceleration speed hence it is 0.2m/s
Answer:
Explanation:
x = 3 Cos (4πt + π/5)
(a) Substitute t = 3 s
x = 3 Cos (12π + π/5)
x = 3 (0.82) = 2.46 m
(b) Velocity, v = dx/dt
v = 3 (-1)(4π) Sin(4πt + π/5)
Substitute t = 3 s
v = - 37.68 Sin(12π + π/5)
v = - 37.68 (0.572)
v = - 21.55 m/s
(c) Acceleration, a = dv/dt
a = 3 (-1)(4π)(4π) Cos(4πt + π/5)
Substitute t = 3 s
a = - 473.26 (0.82)
a = - 388.21 m/s²
(d) Phase = 4πt + π/5
Substitute t = 3 s
Phase = 12 π + π/5 = 38.308 rad
(e) ω = 4π
so, 2πf = 4π
f = 2 Hz
(f) T = 1 / f = 1 / 2 = 0.5 second
Explanation:
Acceleration is change in velocity over change in time:
a = Δv / Δt
a = (10 m/s - 25 m/s) / (240 s - 0 s)
a = -0.0625 m/s²
So the car decelerates at 0.0625 m/s².
