If velocity is decreasing, then acceleration is in the direction
opposite to the velocity.
If the object is moving in the direction that you call 'positive',
then acceleration is negative.
Answer:
a) 1.3 rad/s
b) 0.722 s
Explanation:
Given
Initial velocity, ω = 0 rad/s
Angular acceleration of the wheel, α = 1.8 rad/s²
using equations of angular motion, we have
θ2 - θ1 = ω(0)[t2 - t1] + 1/2α(t2 - t1)²
where
θ2 - θ1 = 53.2 rad
t2 - t1 = 7s
substituting these in the equation, we have
θ2 - θ1 = ω(0)[t2 - t1] + 1/2α(t2 - t1)²
53.2 =ω(0) * 7 + 1/2 * 1.8 * 7²
53.2 = 7.ω(0) + 1/2 * 1.8 * 49
53.2 = 7.ω(0) + 44.1
7.ω(0) = 53.2 - 44.1
ω(0) = 9.1 / 7
ω(0) = 1.3 rad/s
Using another of the equations of angular motion, we have
ω(0) = ω(i) + α*t1
1.3 = 0 + 1.8 * t1
1.3 = 1.8 * t1
t1 = 1.3/1.8
t1 = 0.722 s
C. coil suspended by bearings.
<span>but im not 100% sure</span>
Answer: 2.7 m/s
Explanation:
Given the following :
Period (T) = 8.2 seconds
Radius = 3.5 m
The tangential speed is given as:
V = Radius × ω
ω = angular speed = (2 × pi) / T
ω = (2 × 22/7) / 8.2
ω = 6.2857142 / 8.2
ω = 0.7665505
Therefore, tangential speed (V) equals;
r × ω
3.5 × 0.7665505 = 2.6829268 m/s
2.7 m/s