Answer:
a = 0.7267
, acceleration is positive therefore the speed is increasing
Explanation:
The definition of acceleration is
a = dv / dt
they give us the function of speed
v = - (t-1) sin (t² / 2)
a = - sin (t²/2) - (t-1) cos (t²/2) 2t / 2
a = - sin (t²/2) - t (t-1) cos (t²/2)
the acceleration for t = 4 s
a = - sin (4²/2) - 4 (4-1) cos (4²/2)
a = -sin 8 - 12 cos 8
remember that the angles are in radians
a = 0.7267
the problem does not indicate the units, but to be correct they must be m/s²
We see that the acceleration is positive therefore the speed is increasing
Power = 
Delilah: 170J/30s = 5.66 W
Adam: 260J/20s = 13 W
The acceleration due to gravity would be 5.95 m/s²
A force is known to be a push or pull and it is the change in momentum per time. It can be expressed by using the relation.
- Force = mass × acceleration.
From the parameters given:
- Mass = 105 kg
- Force = 625 N
By replacing the given values into the above equation, we can determine the acceleration.
∴
625 N = 105 kg × acceleration.

acceleration = 5.95 N/kg
acceleration = 5.95 m/s²
Learn more about acceleration(a) here:
brainly.com/question/14344386
Answer:
B)
Explanation:
a brilliant work on all the principles it open up a whole new world and change the world algebraicly