Answer:
a) The angular acceleration of the beam is 0.5 rad/s²CW (direction clockwise due the tangential acceleration is positive)
b) The acceleration of point A is 3.25 m/s²
The acceleration of point E is 0.75 m/s²
Explanation:
a) The relative acceleration of B with respect to D is equal:

Where
aB = absolute acceleration of point B = 2.5 j (m/s²)
aD = absolute acceleration of point D = 1.5 j (m/s²)
(aB/D)n = relative acceleration of point B respect to D (normal direction BD) = 0, no angular velocity of the beam
(aB/D)t = relative acceleration of point B respect to D (tangential direction BD)


We have that
(aB/D)t = BDα
Where α = acceleration of the beam
BDα = 1 m/s²
Where
BD = 2

b) The acceleration of point A is:

(aA/D)t = ADαj

The acceleration of point E is:
(aE/D)t = -EDαj

Explanation:
Below is an attachment containing the solution.
Answer:
A 0m
Explanation:
The horse runs clockwise round the strack, then goes back to the start line ending up back at the same place when it started.
Answer:
for the people of the Earth traveling they last much more than 70 years
Explanation:
In order to answer this answer we must place ourselves in the context of special relativity, which are the expressions for time and displacement since the speed of light has a finite speed that is the same for all observers.
The life time of the person is 70 years in a fixed reference system in the person this time we will call their own time (t₀), when the person is placed in a ship that moves at high speed, very close to the speed of the light the time or that an observer measures on Earth, the expression for this time is
t = t₀ 1 / √(1 - (v / c)²)
We see that if the speed of the ship is very close to the speed of light the
the value of the root of the denominator is very high, for which for the person on Earth it measures a very large time even when the person on the ship travels has a time within its 70 years of life
In concussion, for the people of the Earth traveling they last much more than 70 years
Your answer is C hope i helped
have a good day :)