Answer:
v_{f} = 74 m/s, F = 230 N
Explanation:
We can work on this exercise using the relationship between momentum and moment
I = ∫ F dt = Δp
bold indicates vectors
we can write this equations in its components
X axis
Fₓ t = m ( -v_{xo})
Y axis
t = m (v_{yf} - v_{yo})
in this case with the ball it travels horizontally v_{yo} = 0
Let's use trigonometry to write the final velocities and the force
sin 30 = v_{yf} / vf
cos 30 = v_{xf} / vf
v_{yf} = vf sin 30
v_{xf} = vf cos 30
sin40 = F_{y} / F
F_{y} = F sin 40
cos 40 = Fₓ / F
Fₓ = F cos 40
let's substitute
F cos 40 t = m ( cos 30 - vₓ₀)
F sin 40 t = m (v_{f} sin 30-0)
we have two equations and two unknowns, so the system can be solved
F cos 40 0.1 = 0.4 (v_{f} cos 30 - 20)
F sin 40 0.1 = 0.4 v_{f} sin 30
we clear fen the second equation and subtitles in the first
F = 4 sin30 /sin40 v_{f}
F = 3.111 v_{f}
(3,111 v_{f}) cos 40 = 4 v_{f} cos 30 - 80
v_{f} (3,111 cos 40 -4 cos30) = - 80
v_{f} (- 1.0812) = - 80
v_{f} = 73.99
v_{f} = 74 m/s
now we can calculate the force
F = 3.111 73.99
F = 230 N
Answer:
T = 190 N
Explanation:
When child is sitting on the swing then the weight of the child is vertically downwards
So it is
now a force of 100 N is acting on the swing in horizontal direction
so it is given as
now the net force is resultant force due to gravity and horizontal force
so it is given as
Answer:
(a) 
, 
(b) When 
, object is slowing down, when 
object is speeding up.
Explanation:
(a) To get the velocity function, we need to take the derivative of the position function.
To get the acceleration function, we need to take the derivative of the velocity function.
(b) The object is slowing down when velocity is decreasing by time (decelerating) hence a < 0
On the other hand, object is speeding up when a > 0
Therefore, when 
, object is slowing down, when object is speeding up.
Answer:
small car since they weigh less than a bus
Explanation:
