Answer: A reference point
Explanation: If an object is in motion then its distance from another object is changing. Whether an object is moving or not depends on your point of view. For example, a woman riding on a bus is not moving in relation to the seat she is sitting on, but she is moving in relation to the buildings the bus passes. A reference point is a place or object used for comparison to determine if something is in motion. An object is in motion if it changes position relative to a reference point. You assume that the reference point is stationary, or not moving.
Answer: 
The linear momentum 
is given by the following equation:
(1)
Where 
is the mass and 
the velocity.
On the other hand, the kinetic energy 
is given by:
(2)
Which is the same as:
Now, if we double the kinetic energy, equation (2) changes to:
(3)
So, if we want to obtain the kinetic energy as shown in (3), the only option that works is increasing momentum by a factor of or 
:
Applying this in (2):
>>>As we can see, this equation is the same as equation (3)
Therefore, the correct answer is B
Answer: Option (c) is the correct answer.
Explanation:
An elastic object is defined as the object that is able to retain its shape when a force is applied on it.
For example, when we pull a rubber band then it stretches and when we withdraw the force applied on it then it retain its shape.
As we know that potential energy is the energy obtained by an object due to its position.
So, when we stretch a rubber band then it will have elastic potential energy as position of the rubber band is changing and since, it will retain it shape hence it has elastic potential energy.
Thus, we can conclude that a stretched rubber band has elastic potential energy.
Answer:
The electric force between them is 878.9 N
Given:
Identical charge C
Separation between two charges m
For finding the electrical force,
According to the coulomb's law
Here, force between two balloons are repulsive because both charges are same.
Where N Therefore, the electric force between them is 878.
Explanation:
Answer:
volume of the airspace=0.605m^3
Explanation:
Patm = 10^5 N/m^2
Depth= 60 metres
Pressure at the depth = ?
Density = 1.025 g/cm3 = 1025 kg/m3
P = Patm + hσg
P = 10^5 + 60*1025*9.8
P = 702700 N/m^2
P = 7.027 atm
Since the temperature is constant, Boyle’s law holds
P1V1 = P2V2
P1 = 1 atm
P1, initial pressure of the bell(atm pressure) = 1 atm
The initial volume of the airspace, V1 = 4.25 m^3
Final pressure at the depth = 7.027 atm
Applying the Boyle’s lay
1*4.25 = 7.027 * V2
V2 = 4.25/7.027
V2 = 0.605m^3
