Answer:
Explanation:
Given that,
Initial Angular velocity w=500rpm
Converting from rpm to rad/s
1rev =2πrad
1minutes =60secs
500rpm=500rev/mins
w = 500×2π/60
wi=52.36rad/s
The final angular velocity wf=0rad/s
Time to stop is t=2.6sec
We want to find angular acceleration α
Using the equation of angular motion
wf = wi + αt.
0 = 52.36 + 2.6α
-52.36=2.6α
α = -52.36/2.6
α = -20.14rad/s²
The angular acceleration is negative because it is decelerating.
Then, α=20.14rad/s²
C the correct but not sure?
Answer:
A drunk driver's car travel 49.13 ft further than a sober driver's car, before it hits the brakes
Explanation:
Distance covered by the car after application of brakes, until it stops can be found by using 3rd equation of motion:
2as = Vf² - Vi²
s = (Vf² - Vi²)/2a
where,
Vf = Final Velocity of Car = 0 mi/h
Vi = Initial Velocity of Car = 50 mi/h
a = deceleration of car
s = distance covered
Vf, Vi and a for both drivers is same as per the question. Therefore, distance covered by both car after application of brakes will also be same.
So, the difference in distance covered occurs before application of brakes during response time. Since, the car is in uniform speed before applying brakes. Therefore, following equation shall be used:
s = vt
FOR SOBER DRIVER:
v = (50 mi/h)(1 h/ 3600 s)(5280 ft/mi) = 73.33 ft/s
t = 0.33 s
s = s₁
Therefore,
s₁ = (73.33 ft/s)(0.33 s)
s₁ = 24.2 ft
FOR DRUNK DRIVER:
v = (50 mi/h)(1 h/ 3600 s)(5280 ft/mi) = 73.33 ft/s
t = 1 s
s = s₂
Therefore,
s₂ = (73.33 ft/s)(1 s)
s₂ = 73.33 ft
Now, the distance traveled by drunk driver's car further than sober driver's car is given by:
ΔS = s₂ - s₁
ΔS = 73.33 ft - 24.2 ft
<u>ΔS = 49.13 ft</u>
It should be A.
A ball bouncing is moving so if it’s moving that means it has kinetic energy. It also has potential energy because when it hits the floor it kind of stops so it has potential.
-Hope this helps.
Answer:
v = 18.84 m/s
Explanation:
Given that,
The length of the string, r = 1.5 m (it will act as radius)
The rubber stopper makes 120 complete circles every minute.
Since, 1 minute = 60 seconds
It means, its frequency is 2 circles every second.
Let we need to find the average speed of the rubber stopper. It can be calculated as follows :
d is distance, 
and 1/T = f (frequency)
So, the average speed of the rubber stopper is 18.84 m/s.
