<h2>
Answer:</h2>
(a) 10N
<h2>
Explanation:</h2>
The sketch of the two cases has been attached to this response.
<em>Case 1: The box is pushed by a horizontal force F making it to move with constant velocity.</em>
In this case, a frictional force
is opposing the movement of the box. As shown in the diagram, it can be deduced from Newton's law of motion that;
∑F = ma -------------------(i)
Where;
∑F = effective force acting on the object (box)
m = mass of the object
a = acceleration of the object
∑F = F - 
m = 50kg
a = 0 [At constant velocity, acceleration is zero]
<em>Substitute these values into equation (i) as follows;</em>
F -
= m x a
F -
= 50 x 0
F -
= 0
F =
-------------------(ii)
<em>Case 2: The box is pushed by a horizontal force 1.5F making it to move with a constant velocity of 0.1m/s²</em>
In this case, the same frictional force
is opposing the movement of the box.
∑F = 1.5F - 
m = 50kg
a = 0.1m/s²
<em>Substitute these values into equation (i) as follows;</em>
1.5F -
= m x a
1.5F -
= 50 x 0.1
1.5F -
= 5 ---------------------(iii)
<em>Substitute </em>
<em> = F from equation (ii) into equation (iii) as follows;</em>
1.5F - F = 5
0.5F = 5
F = 5 / 0.5
F = 10N
Therefore, the value of F is 10N
<em />
Answer:
i) Distancia, ii) La cinta métrica es impracticable.
Explanation:
i) El concepto físico que se construye únicamente del punto de salida y el punto de llegada a la Luna es el concepto de desplazamiento, definido como la distancia en línea recta de un punto en el espacio con respecto a un punto de referencia (la Tierra en este caso).
La distancia puede involucrar trayectorias curvilíneas entre los puntos mencionados.
ii) Por último, el uso de una cinta métrica es impracticable debido a la cantidad de material a utilizar y los efectos gravitacionales, electromagnéticos y mecánicos que inducen a una deflexión o una ruptura de esa cinta debido a la magnitud de la distancia entre las superficies del planeta y el satélite, respectivamente.
En este caso, es mejor utilizar la medición con tecnología láser, basadas en el fenómeno del electromagnetismo.
Answer:
The speed of the skier after moving 100 m up the slope are of V= 25.23 m/s.
Explanation:
F= 280 N
m= 80 kg
α= 12º
μ= 0.15
d= 100m
g= 9,8 m/s²
N= m*g*sin(α)
N= 163 Newtons
Fr= μ * N
Fr= 24.45 Newtons
∑F= m*a
a= (280N - 24.5N) / 80kg
a= 3.19 m/s²
d= a * t² / 2
t=√(2*d/a)
t= 7.91 sec
V= a* t
V= 3.19 m/s² * 7.91 s
V= 25.23 m/s

GiveN:
- Initial velocity = 9.8 m/s²
- Accleration due to gravity = -9.8 m/s²
- Time taken = 1 s
To FinD:
- Final velocity of the ball?
Step-by-step Explanation:
Using the first Equation of motion,
⇒ v = u + gt
⇒ v = 9.8 + -9.8(1)
⇒ v = 0 m/s
The final velocity is hence <u>0</u><u> </u><u>m</u><u>/</u><u>s</u><u>.</u>
<h3>
Note:</h3>
- While solving questions of under gravity motions using equations of motion, remember the sign convection to avoid mistakes.
- You can consider positive above the ground and negative for towards it.