Answer:
Explanation:
Given that:
A circuit with a lagging 0.7 pf delivers 1500 watts and 2100VA
Here:
the initial power factor i.e cos θ₁ = 0.7 lag
θ₁ = cos⁻¹ (0.7)
θ₁ = 45.573°
Active power P = 1500 watts
Apparent power S = 2100 VA
What amount of vars must be added to bring the pf to 0.85
i.e the required power factor here is cos θ₂ = 0.85 lag
θ₂ = cos⁻¹ (0.85)
θ₂ = 31.788°
However; the initial reactive power 
= P×tanθ₁
the initial reactive power = 1500 × tan(45.573)
the initial reactive power = 1500 × 1.0202
the initial reactive power = 1530.3 vars
The amount of vars that must therefore be added to bring the pf to 0.85
can be calculated as:
Answer:
A) 667 J
B) 381.4 J
C) 0 J
D) 245.4 J
E) 40.2J
F) 2 m/s
Explanation:
Let g = 9.81 m/s2
A) The work done on the suitcase is the product of the force applied and the distance travelled:
w = Fs = 145 * 4.6 = 667 J
B) The work done by gravitational force the dot product between the gravity vector and the distance vector
C) As the normal force vector is perpendicular to the distance vector, the work done by the normal force is 0
D) The work done on the suitcase by friction force is the product of the force applied and the distance travelled, whereas friction force is the product of normal force and coefficient
E) The total workdone on the suite case would be the pulling work subtracted by gravity work and friction work
F) As the suit case has 0 kinetic and potential energy at the bottom, and the total work done is converted to kinetic energy at 4.6 m along the ramp, we can conclude that:
Explanation:
It is given that,
Speed of the sports car, v = 85 mph = 37.99 m/s
The radius of curvature, r = 525 m
Let 
is the normal weight and 
is the apparent weight of the person. Its apparent weight is given by :
So, 
or
Hence, this is the required solution.
Answer:
The mild climate enabled Romans to grow wheat, grapes, and olives. This abundance o food supported the people and allowed Rome to prosper. While the climate made year-long agriculture possible, Rome also had the advantage to be near water. The Tiber River helped the agricultural system to prosper
Explanation:
