Answer:
160N
Explanation: When 80kg mass is one group . It's reaction force acting on a ground.
Weight of the object = 80*10
= 800 N
Here we are given cofficient of static friction its 0.2. It should be smaller than 1
Friction force = Reaction * Friction Cofficient
Reaction = 800N ( Considering Vertical Equilibrium )
F = 800* 0.2
F = 160N
If two forces act on an object in the same direction, the net force is equal to the sum of the two forces
Answer:
v = 2 v₀
Explanation:
For this exercise we will use the relationship between work and the change in kinetic energy
W = ΔK
Where the work is of the friction force, which is always opposed to the movement whereby the angle is 180º
W = - fr x
The distance for the first case is
x = 1/4 L
We substitute
-fr ¼ L = ½ m v₀²
fr L = 2 m v₀²
In the second case, the new speed takes the ball the entire distance
x = d
-fr L = ½ m v²
We equal the two equations
2 m v₀² = ½ m v²
v² = 4 v₀²
v = 2 v₀
Answer:
Second ball
Explanation:
When a ball is thrown up with a certain velocity when the object reaches the same point from where it was thrown the velocity of the object becomes equal to the velocity with which the ball was thrown.
First ball
Second ball
Third ball
From the equations above it can be seen that the second ball will have the highest velocity when it hits the ground.
So, 
Answer:
Pretty sure it is air mass C
Explanation:
It looks like yhe air has warm air where as the other 2 options have cold air.
