Answer:
(a) 37.5 kg
(b) 4
Explanation:
Force, F = 150 N
kinetic friction coefficient = 0.15
(a) acceleration, a = 2.53 m/s^2
According to the newton's second law
Net force = mass x acceleration
F - friction force = m a
150 - 0.15 x m g = m a
150 = m (2.53 + 0.15 x 9.8)
m = 37.5 kg
(b) As the block moves with the constant speed so the applied force becomes the friction force.

Answer:

Explanation:
m = Masa del coche
g = Aceleración debida a la gravedad = 
h = Altura = 
v = Velocidad del automóvil en la parte inferior de la pista
Aquí asumimos que el automóvil desciende verticalmente. La energía potencial del automóvil se completará convertida en energía cinética en la parte inferior de la pista ya que no hay pérdida de energía.

La velocidad máxima que puede alcanzar el coche es
.
Force=mass*acceleration
F=ma
20=2.8a
a=20/2.8
a=7.14 m/s^2
Answer:
5.87 m, 75.5°
Explanation:
Let's say C is the resultant vector.
The x component is the sum of the x components of A and B.
Cx = Ax + Bx
Cx = 10.1 cos 60° + 7.3 cos 275°
Cx = 5.69
The y component is the sum of the y components of A and B.
Cy = Ay + By
Cy = 10.1 sin 60° + 7.3 sin 275°
Cy = 1.47
The magnitude is found with Pythagorean theorem, and the angle is found with trigonometry.
C² = Cx² + Cy²
C² = 5.69² + 1.47²
C = 5.87
θ = atan(Cy / Cx)
θ = atan(5.69 / 1.47)
θ = 75.5°