(if it's frictionless the length doesn't even matter :) )
It would have the same kinetic energy down as the potential energy up. That is,

or

(the mass doesn't even matter). The result is

, so only the height matters really. It is almost 9 (it is

).
Answer:

Explanation:
Let's assume that an object is launched straight upward in a gravitational field. Its initial kinetic energy is given by
(1)
where m is the mass and v is the initial speed.
As the object goes higher, its kinetic energy decreases and it is converted into gravitational potential energy, since the total mechanical energy (sum of kinetic and potential energy) must remain constant:

At the highest point of the trajectory, the speed of the object is zero (v=0), so the kinetic energy is also zero (K=0), which means that all the kinetic energy has been converted into potential energy:
(2)
where g is the gravitational acceleration and h is the maximum height of the object.
Due to conservation of energy, we can write that (1) and (2) are equal, so:

from which we can derive an expression for the maximum height reached by the object

Answer:
Explanation:
Using conservation law of momentum
let m₁ = mass of the railroad, initial u₁ = 3.49 m/s
let m₂ = mass of one of the coupled car, u₂= 1.28m/s
let m₃ = mass of the second car u₃ = 1.28 m/s
m₁u₁ + m₂u₂ + m₃u₃ = v ( m₁ + m₂ + m₃)
since the masses are the same
m₁ = m₂ = m₃
m ( 3.49 + 1.28 + 1.28) = 3m v
6.05 m = 3 mv
v = 6.05 m / 3m = 2.0167 m/s
b) kinetic energy lost = energy before collision - energy after collision
= (0.5m₁u₁² + 0.5 ( m₁+m₂) u₂² - 0.5 ( m₁ + m₂ + m₃) v
= (6.58365 + 1.7712) - 6.5951 = 1.76J
Answer:
The force on the charge at the origin is 0 N .
Explanation:
All charges are positive. So, in x axis force exerted by the charge located in the position (10 cm, 0 cm) will be canceled with the force exerted by the charge located in the position (-10 cm, 0 cm). In the same way, in y axis the force exerted by the charge located in the position (0 cm, 10 cm) will be canceled with the force exerted by the charge located in the position (0 cm, -10 cm).
Answer:

Explanation:
Potential difference between two points in constant electric field is given by the formula

here we know that

also we know that

now we have

now change in potential energy is given as


