Answer:
Explanation:
The options is not well presented
This are the options
A. θ = at³ + b
B. θ = at² + bt + c
C. θ = at² — b
D. θ = Sin(at)
So, we want to prove which of the following option have a constant angular acceleration I.e. does not depend on time
Now,
Angular acceleration can be determine using.
α = d²θ / dt²
α = θ''(t)
So, second deferential of each θ(t) will give the angular acceleration
A. θ = at³ + b
dθ/dt = 3at² + 0 = 3at²
d²θ/dt² = 6at
α = d²θ/dt² = 6at
The angular acceleration here still depend on time
B. θ = at² + bt + c
dθ/dt = 2at + b + 0 = 2at + b
d²θ/dt² = 2a + 0 = 2a
α = d²θ/dt² = 2a
Then, the angular acceleration here is constant is "a" is a constant and the angular acceleration is independent on time.
C. θ = at² —b
dθ/dt = 2at — 0 = 2at
d²θ/dt² = 2a
α = d²θ/dt² = 2a
Same as above in B. The angular acceleration here is constant is "a" is a constant and the angular acceleration is independent on time.
D. θ = Sin(at)
dθ/dt = aCos(at)
d²θ/dt² = —a²Sin(at) = —a²θ
α = d²θ/dt² = -a²θ
Since θ is not a constant, then, the angular acceleration is dependent on time and angular displacement
So,
The answer is B and C
Half mass car because it's traveling faster
When you put ice in the freezer, the water expands when in gets cold.
the sidewalks have cracks in them to make room for the expansion and contraction when it heats up and cools down.
as you drive a car, the heat from combustion causes metal to expand. when you turn the car off, the metal cools down and contracts
Answer:
Average speed of Elain = 60 km/h
Explanation:
Total Distance covered by Jack = 360km
Average Speed of Jack = 80 km/h
Time taken by Jack to complete his journey = Distance / Average speed = 360 km / 80 km/h
Time taken by Jack to complete his journey = 4.5 hours
As it is given the both Jack and Elain travelled the same amount of distance:
Total distance travelled by Elain = 360 km
It is given that Elain took 1.5 hourse more than Jack to cover the distance, so Time taken by Elain to cover the distance is = 4.5 hours + 1.5 hours = 6 hours
Average speed of Elain = Distance/ time = 360 km / 6 hours
Average speed of Elain = 60 km/h
