Answer:
a = F-ff/m
Explanation:
According to Newton's second law of motion which states that "the rate of change in momentum of a body is directly proportional to the applied force F and acts in the direction of the force.
Mathematically;
F = ma
Since two forces acts on the cart i.e the moving force F and the frictional force Ff , we will take the sum of the forces.
∑F = ma where
m is the mass of the cart
a is its acceleration
∑F = F+(-ff )(since frictional force is an opposing force)
F - ff = ma
Dividing both sides by mass m
a = F-ff/m
Answer:
a) μ = 0.475
, b) μ = 0.433
Explanation:
a) For this exercise of Newton's second law, we create a reference system with the x-axis parallel to the plane and the y-axis perpendicular to it
X axis
Wₓ - fr = m a
the friction force has the expression
fr = μ N
y Axis
N -
= 0
let's use trigonometry for the components the weight
sin 27 = Wₓ / W
Wₓ = W sin 27
cos 27 = W_{y} / W
W_{y} = W cos 27
N = W cos 27
W sin 27 - μ W cos 27 = m a
mg sin 27 - μ mg cos 27 = m a
μ = (g sin 27 - a) / (g cos 27)
very = tan 27 - a / g sec 27
μ = 0.510 - 0.0344
μ = 0.475
b) now the block starts with an initial speed of 3m / s. In Newton's second law velocity does not appear, so this term does not affect the result, the change in slope does affect the result
μ = tan 25 - 0.3 / 9.8 sec 25
μ = 0.466 -0.03378
μ = 0.433
5.55 mol H2O
Explanation:
Water has a molar mass of 18.01528 g/mol. We can then calculate the number of moles of water as
100 g H20 × (1 mol H2O/18.01528 g H20)
= 5.55 mol H2O