Answer:
A
Explanation:
Because D is definitely true and there is only one false sentence what means if that non of B or C is false because if one is false so other one needs to be too.
Answer:
39.81 N
Explanation:
I attached an image of the free body diagrams I drew of crate #1 and #2.
Using these diagram, we can set up a system of equations for the sum of forces in the x and y direction.
∑Fₓ = maₓ
∑Fᵧ = maᵧ
Let's start with the free body diagram for crate #2. Let's set the positive direction on top and the negative direction on the bottom. We can see that the forces acting on crate #2 are in the y-direction, so let's use Newton's 2nd Law to write this equation:
- ∑Fᵧ = maᵧ
- T₁ - m₂g = m₂aᵧ
Note that the tension and acceleration are constant throughout the system since the string has a negligible mass. Therefore, we don't really need to write the subscripts under T and a, but I am doing so just so there is no confusion.
Let's solve for T in the equation...
- T₁ = m₂aᵧ + m₂g
- T₁ = m₂(a + g)
We'll come back to this equation later. Now let's go to the free body diagram for crate #1.
We want to solve for the forces in the x-direction now. Let's set the leftwards direction to be positive and the rightwards direction to be negative.
The normal force is equal to the x-component of the force of gravity.
- (F_n · μ_k) - m₁g sinΘ = m₁aₓ
- (F_g cosΘ · μ_k) - m₁g sinΘ = m₁aₓ
- [m₁g cos(30) · 0.28] - [m₁g sin(30)] = m₁aₓ
- [(6)(9.8)cos(30) · 0.28] - [(6)(9.8)sin(30)] = (6)aₓ
- [2.539595871] - [-58.0962595] = 6aₓ
- 60.63585537 = 6aₓ
- aₓ = 10.1059759 m/s²
Now let's go back to this equation:
We have 3 known variables and we can solve for the tension force.
- T = 2(10.1059759 + 9.8)
- T = 2(19.9059759)
- T = 39.8119518 N
The tension force is the same throughout the string, therefore, the tension in the string connecting M2 and M3 is 39.81 N.
Answer:
0 J
Explanation:
From the diagram below; we would notice that the Force (F) = Tension (T)
Also the angle θ adjacent to the perpendicular line = 90 °
The Workdone W = F. d
W = Fd cos θ
W = Fd cos 90°
W = Fd (0)
W = 0 J
Hence the force is perpendicular to the direction of displacement and the net work done in a circular motion in one complete revolution is = 0
Answer:
10 m/s
Explanation:
The problem can be solved by using the law of conservation of momentum: the initial momentum has to be equal to the final momentum, so we can write the following
where
is the mass of the first car
is the initial velocity of the first car
is the mass of the second car
is the initial velocity of the second car
is the final velocity of the two combined cars after the collision
Re-arranging the equation and substituting the numbers, we find