Answer:True. The number of calories in a food is a measure of how much potential energy that food possesses.
Explanation:
Answer:
m = 62.14 g
Explanation:
Energy used to melt the ice is the energy released by the condensation of the water forms on the glass
so here we have
energy for the condensation of water is given as
let mass of water condensed = m

now the energy of vaporization is given as

here we know that


Now we have


Wave speed = (wavelength) x (frequency)
= (4 m) x (2 /sec)
= 8 m/sec
Answer:
The gravitational force is related to the mass of each object.
The gravitational force is an attractive force.
Explanation:
Gravitational force is a long range force of attraction between any two masses.
Mathematically given as :

where:
are the masses
r= distance between the center of mass of the two objects.
G= gravitational constant = 
From the above relation of eq. (1) it is clear that,
Gravitational force is inversely proportional to the square of the distance and directly proportional to the masses.
The mass of an object is independent of its size due to the fact that density may vary for different objects.
The force of gravity varies with height as:

where:

gravity at height
of the center of mass of the object from the center of mass of the earth.
and we know that force:

where: m= mass of the object.
Answer:
F = 0
Explanation:
The magnetic force is described by two expressions
for a moving charge
F = q v x B
for a wire with a current
F = I L xB
bold indicates vectors
let's write this equation in module form
F = I L B sin θ
where the angle is between the direction of the current and the direction of the magnetic field
In this case they indicate that the cable goes from the South wall to the North wall, so this is the direction of the current
The magnetic field of the Earth goes from the south to the north and in this part it is horizontal
Therefore the current and the magnetic field are parallel, the angle between them is zero
sin 0 = 0
consequently the magnetic force is zero
F = 0