Answer:
The net friction force is 8.01 N
Explanation:
Net friction force = mass of hockey puck × acceleration
From the equations of motion
v^2 = u^2 + 2as
v = 40 m/s
u = 0 m/s (puck was initially at rest)
s = 30 m
40^2 = 0^2 + 2×a×30
60a = 1600
a = 1600/60 = 26.7 m/s^2
The acceleration of the puck is 26.7 m/s^2
Net friction force = 0.3 × 26.7 = 8.01 N
Answer:
velocity = 62.89 m/s in 58 degree measured from the x-axis
Explanation:
Relevant information:
Before the collision, asteroid A of mass 1,000 kg moved at 100 m/s, and asteroid B of mass 2,000 kg moved at 80 m/s.
Two asteroids moving with velocities collide at right angles and stick together. Asteroid A initially moving to right direction and asteroid B initially move in the upward direction.
Before collision Momentum of A = 1000 x 100 =
kg - m/s in the right direction.
Before collision Momentum of B = 2000 x 80 = 1.6 x
kg - m/s in upward direction.
Mass of System of after collision = 1000 + 2000 = 3000 kg
Now applying the Momentum Conservation, we get
Initial momentum in right direction = final momentum in right direction =
And, Initial momentum in upward direction = Final momentum in upward direction = 1.6 x
So,
=
m/s
and
m/s
Therefore, velocity is = 
= 
= 62.89 m/s
And direction is
tan θ =
= 1.6
therefore, 
=
from x-axis
I attached the missing picture.
The force of seat acting on the child is a reaction the force of child pressing down on the seat. This is the third Newton's law. The force of a child pressing down the seat and the force of the seat pushing up on the child are the same.
There two forces acting on the child. The first one is the gravitational force and the second one is centrifugal force. In this example, the force of gravity is always pulling down, but centrifugal force always acts away from the center of circular motion.
Part AFor point A we have:

In this case, the forces are aligned, centrifugal is pointing up and gravitational is pulling down.
Part BAt the point, B situation is a bit more complicated. In this case force of gravity and centrifugal force are not aligned. We have to look at y components of this forces, y-axis, in this case, is just pointing upward.
Part CThe child will stay in place at point A when centrifugal force and force of gravity are in balance:
Resistors tell me if im right