Answer:
a) 
b) imagen adjunta
Explanation:
a) Primero debemos hacer la conversión de 81 km/h a m/s, esto es 22.5 m/s.
Ahora, usando la ecuacion cinemática, en un movimiento acelerado tenemos:

Queremos encontrar la posición hasta detenerse, osea vf = 0.



b) Para este caso el gráfico se encuentra adjunto.
Espero que te sirva de ayuda!
Answer:
(a) 91 kg (2 s.f.) (b) 22 m
Explanation:
Since it is stated that a constant horizontal force is applied to the block of ice, we know that the block of ice travels with a constant acceleration and but not with a constant velocity.
(a)

Subsequently,

*Note that the equations used above assume constant acceleration is being applied to the system. However, in the case of non-uniform motion, these equations will no longer be valid and in turn, calculus will be used to analyze such motions.
(b) To find the final velocity of the ice block at the end of the first 5 seconds,

According to Newton's First Law which states objects will remain at rest
or in uniform motion (moving at constant velocity) unless acted upon by
an external force. Hence, the block of ice by the end of the first 5
seconds, experiences no acceleration (a = 0) but travels with a constant
velocity of 4.4
.

Therefore, the ice block traveled 22 m in the next 5 seconds after the
worker stops pushing it.
The normal force acts to counter the gravitational force, that is the upward direction.
Answer
22.5 m/s
Explanation
We shall use the trigonometric ratio cosine to find the horizontal component.
cos = adjacent/hypotenuse
Adjacent is the horizontal and hypotenuse is the fly speed.
cos 30° = horizontal / 26
horizontal velocity = 26 × cos 30°
= 26 × 0.866
= 22.5166
= 22.5 m/s
The blades that spin around in the fan, because they are flat and produce work