Recent content by PepeF.

Homework Statement The damage caused by electric shock depends on the current flowing through the body; 1 mA can be felt and 5 mA is painful. Above 15 mA, a person loses muscle control, and 70 mA can be fatal. A person with dry skin has a resistance from one arm to the other of about 1.1 ×...

it says determine the charge for this to happen

Homework Statement An Electron remains suspended between the Earth (assumed nueutral) and a fixed positive point charge, at a distance of 6.37 m from the point charge. Determine the charge for this to happen. answer must be in C. Homework Equations g= 9.8 m/s^2 Coulomb constant = 8/98755e9 N*...

Homework Statement a force of 5.02N acts on a 4kg object for 23.3s. momentum is 116.966 N*s Homework Equations what is the change in velocity?

Homework Statement a 1.83x10^3 kg car accelerates uniformly from rest to 13.6m/s in 2.81 s -what is the work done on the car in this time inerval? -what is the power delivered by the engine in thsi time interval? Homework Equations w=f*d p=w/t The Attempt at a Solution...

Homework Statement a weight lifter lifts a set of weights a vertical distance of 3.64 m. if a constant net force of 394 N is exerted on the weights, how much net work is done on the weights ? Homework Equations i need net work formula The Attempt at a Solution

Homework Statement a .459kg raindrop falls vertically at constant speed under the influence of gravity and air resistance. acceleration due to gravity is 9.8 m/s after the drop 141 m, the work done by gravity is 634.246 J a problem ask the work donde by air resistance the work done by...

Homework Statement two 3.5g bullets are fired with speeds of 42.4 m/s and the 2nd one with 69.6 m/s what is the kinetic energy of the first bullet? the second one? Homework Equations EK=(1/2)mv^2 The Attempt at a Solution EK=(1/2)3.6*42.4^2 = 3235.968 it is wrong.. why?

Homework Statement a shopper pushes a cart with a force of 35N directed at an angle of 26' downward from the horisontal. find the work done if he pushes the cart for 50.7m Homework Equations w=(f)(cos 0)(Δx) f= w/(cos 0)(Δx) The Attempt at a Solution i did but i got it...

i don't know where to start

i don't even know where to start I am lost

a weight is lifted 3.64m if a constant net force of 394N is exerted on the weights, how much net work is done on the weights? in J that is..

On planet X, an object weights 18.6N. Planet B, the magnitude of the free-fall acceleration is 1.42g (g=9.8m/s2) is the gravitational acceleration on earth) the object weights 29.8N acceleration of gravity is 9.8 m/s2. a) what is the mass (kg) of the object on planet X? b) what is the...

a 5.3g bullet leaves the muzzle of a rifle with a speed of 618.9 m/s. What constants force (N) is exerted on the bullet while it is traveling down the 0.8m lengh of the barrel of the riffle?

Homework Statement the force of air resistance on a raindrop is 5.3x10-5N when it falls with a erminal velocity of 5.3 m/s. the acceleration of gravity is 9.8 m/s2. what is the MASS in Kg of the raindrop? [i am completely lost in this one]