This is where we have to admit that gravitational potential energy is
one of those things that depends on the "frame of reference", or
'relative to what?'.
Potential energy = (mass) x (gravity) x (<em>height</em>).
So you have to specify <em><u>height above what</u></em> .
-- With respect to the ground, the ball has zero potential energy.
(If you let go of it, it will gain zero kinetic energy as it falls to
the ground.)
-- With respect to the floor in your basement, the potential energy is
(3) x (9.8) x (3 meters) = 88.2 joules.
(If you let go of it, it will gain 88.2 joules of kinetic energy as it falls
to the floor of your basement.)
-- With respect to the top of that 10-meter hill over there, the potential
energy is
(3) x (9.8) x (-10) = -294 joules
(Its potential energy is negative. After you let go of it, you have to give it
294 joules of energy that it doesn't have now, in order to lift it to the top of
the hill <em>where it will have zero</em> potential energy.)
Answer:
The speed of the two cars after coupling is 0.46 m/s.
Explanation:
It is given that,
Mass of car 1, m₁ = 15,000 kg
Mass of car 2, m₂ = 50,000 kg
Speed of car 1, u₁ = 2 m/s
Initial speed of car 2, u₂ = 0
Let V is the speed of the two cars after coupling. It is the case of inelastic collision. Applying the conservation of momentum as :
V = 0.46 m/s
So, the speed of the two cars after coupling is 0.46 m/s. Hence, this is the required solution.
Answer:
Explanation:
Using:
Force = electric field * charge
Force = magnitude of charge * velocity * magnetic field * sin tither
Force on particle due to electric field:
Force on particle due to magnetic field:
is in the positive x direction as 
is in the negative x direction while net force is in the positive x direction.
Magnetic field is in the positive Z direction, net force is in the positive x direction.
According to right hand rule, Force acting on particle is perpendicular to the direction of magnetic field and velocity of particle. This would mean the force is along the y-axis. As this is a negatively charged particle, the direction of the velocity of the particle is reversed. Therefore velocity of particle, v, has to be in the negative y direction.
Now,
Answer:
According to Einstein's famous equation, matter can convert into energy (and viceversa) as follows:
where
E is the energy
m is the mass
c is the speed of light (
)
Given the huge value of 
, we see that even a tiny amount of matter is able to release a huge amount of energy, when the whole mass is converted into energy. This is precisely what happens in nuclear reactions. For example, in the process of nuclear fusion (that occurs in the core of the stars), two light nuclei fuse together into a heavier nucleus. The mass of the final nucleus is lower than the total mass of the initial nuclei, so part of the mass has been converted into energy according to the equation above: this is why the amount of energy produced by stars is so big.
Answer:
time of fall and the final velocity
Explanation:
the mass of solid ball is more than the mass of hollow ball.
According to the third equation of motion
v² = u² + 2gh
As the final velocity v does not depend on the mass of the object, so the final velocity of both the ball is same.
According to the first equation of motion
v = u + gt
As v is same for both the balls, the time is also same for both the balls.
So, they both have same time of fall and final velocity.
