The answer is 570 J. The kinetic energy has the formula of 1/2mV². The total work in this process W= 1/2m(V2²-V1²) = 1/2 * 15.0 * (11.5²-7.50²) = 570 J.
The characteristics of the scalar product allows to find the angle between the two vectors is:
The scalar product is the product between two vectors whose result is a scalar.
A . B = |A| |B| cos θ
Where A and B are the vectors, |A| and |B| are the modules of the vectors and θ at the angle between them.
The vector is given in Cartesian coordinates and the unit vectors in these coordinates are perpendicular.
i.i = j.j = 1
i.j = 0
A . B = (4 i - 4j). * -5 i + 7j)
A . B = - 4 5 - 4 7
A. B = -48
We look for the modulus of each vector.
|A| =
|A| =
|A| = 4 √2
|B| =
|B| = 8.60
We substitute.
-48 = 4√2 8.60 cos θ
-48 = 48.66 cos θ
θ = cos⁻¹
θ = 170º
In conclusion using the dot product we can find the angle between the two vectors is:
Learn more about the scalar product here: brainly.com/question/1550649
I believe the answer is B. let me know If I was right.
Answer:
The power transmitted to the pulley is 0.0455 hp.
Explanation:
Given;
mass attached to the rope, m = 5 lb
radius of the pulley, r = 3 in
constant rate of fall of the mass, v = 5 ft/s
acceleration due to gravity, g = 32.2 ft/s²
1 lbf = 32.2 lb.ft/s²
The power transmitted to the pulley is calculated as;
P = Fv
P = (mg)v

in horse power, the power transmitted is calculated as;

Therefore, the power transmitted to the pulley is 0.0455 hp.