Recent content by jbjohnybaker

Anyone?

Homework Statement Three point charges, q₁= -5.00 μC, q₂= -4.00 μC, and q₃ which is negative are arranged as shown on three corner of side a=0.500 m. The direction of the forces on q₁ is at +20.0° with respect to the + x axis. Calculate the magnitude of q₃. The diagram looks something like...

why is the tension 0 if it is acting down with the gravity.. i know that the tension is suppose to be 0 but i don't understand why :S

Homework Statement A child, sitting in the backseat of a car traveling at 20 m/s, throws a ball at 2 m/s to her brother who is siting in the front seat. a. what is the velocity of the ball relative to the children? b. what is the velocity of the ball relative to the road? V of car = 20m/s V of...

Homework Statement A baseball traveling horizontally at 41m/s [S] is hit by a baseball bat, causing its velocity to become 47 m/s [N]. The ball is in contact with the bat for 1.9 ms, and undergoes constant acceleration during this interval. What is that acceleration?Homework Equations V2 = v1...

Homework Statement A child's toy shoots a rubber dart of mass 7.8g, using a compressed spring with a force constant of 3.5 x 10^2 N/m. The spring is initially compressed 4.5cm. All the elastic potential energy is converted into kinetic energy of the dart. What is the speed of the dart as it...

Homework Statement 2. A child's toy shoots a rubber dart of mass 7.8g, using a compressed spring with a force constant of 3.5 x 10^2 N/m. The spring is initially compressed 4.5cm. All the elastic potential energy is converted into kinetic energy of the dart. What is the speed of the dart as it...

okay.. thank you

Homework Statement A pen of mass 0.057 kg slides across a horizontal desk. In sliding 25 cm, its speed decreases to 5.7 cm/s. The force of kinetic friction exerted on the pen by the desk has a magnitude of 0.15N. Apply the law of conservation of energy to determine the initial speed of the...

thank you very much.

is it right? eg = (68.5)(sin13.5)(9.81)(2560)

I have been taught that "the value of delta y is the vertical displacement of the object. This means that the horizontal path of an object follows in changing its vertical height is not significant" :S

Homework Statement A 68.5-kg skier rides a 2.56-km ski lift from the base of a mountain to the top. The lift is at an angle of 13.9° to the horizontal. Determine the skier’s gravitational potential energy at the top of the mountain relative to the base of the mountain. Homework Equations Eg=...

i solved it..thank you very much

W = (F)(D) cos 0 W = (3.85x10^5)(2.45x10^6) cos 0 W = 9.4 x 10^11 J W = 1/2mv^2f - 1/2mv^2i 9.4x10^11 = 1/2(4.55^14)vf^2 - 1/2 (4.55x10^4)(1.22x10^4)^2 9.4x10^11 = 1/2(4.55^14)vf^2 - 3.38611 x10^12 9.4x10^11 + 3.38611 x10^12 = 1/2(4.55^14)vf^2 4.8011 x10^12 = 1/2(4.55^14)vf^2 vf =...