This question is true because it just is
Their momentum is the same.
momentum of dolphin=50kg*16.4m/s=820kg*m/s
momentum of elephant=4100kg*0.20m/s=820kg*m/s
Heat
You can usually warm something by adding energy. The added energy can be from light, electricity, friction, a chemical reaction, nuclear reaction, or any other kind of energy. When first added to a substance, energy might be concentrated in one atom, but this one will soon bump into others and spread the energy. Eventually, every atom or molecule in the substance will move a bit faster. When the added energy is spread throughout a substance, it is then called heat energy, thermal energy, or, simply heat. All three terms mean the same thing. Heat is a form of energy, so it has the units of energy. In the SI system, this is Joules. Many other units to measure thermal energy are in common use. Calories and BTU's are common heat units.
Temperature
You cannot measure heat directly, but you can detect its effect on a substance. Changes in heat can usually be detected as changes in temperature. Usually, when you add energy to a bunch of atoms they move faster and get hotter. Similarly, if you remove energy from a bunch of atoms, they usually move less and get cooler.
Answer:
Zero
Explanation:
Two long parallel wires each carry the same current I in the same direction. The magnetic field in wire 1 is given by :

Magnetic force acting in wire 2 due to 1 is given by :


Similarly, force acting in wire 1 is given by :
According to third law of motion, the force acting in wire 1 will be in opposite direction to wire 2 as :

So, the total magnetic field at the point P midway between the wires is in what direction will be zero as the the direction of forces are in opposite direction.