Answer:
The Heavier Firefighter
Explanation:
Generally, more massive objects will have more intertia than less massive objects. As such it takes more force to halt a more massive object if its moving at the same speed as a smaller object. This can also be thought of in the context of Newton's second law. The more force needed to accelerate an object means the more force the object will have.
Answer:
Potential
Explanation:
The water in the bathtub has more potential energy than that in the tea cup because it has a greater number of water molecules.
Mass is a parameter that is very instrumental in determining potential energy.
The potential energy of a body is the energy due to the position of that body.
Potential energy = mass x acceleration due gravity x height
Mass is the amount of matter in a substance. Water in the tub will have more mass and contain a greater number of water molecules there in.
Since potential energy is directly proportional to mass, then, it will have a greater amount of potential energy.
Answer: W =
J
Explanation: Since the potassium ion is at the outside membrane of a cell and the potential here is lower than the potential inside the cell, the transport will need work to happen.
The work to transport an ion from a lower potential side to a higher potential side is calculated by

q is charge;
ΔV is the potential difference;
Potassium ion has +1 charge, which means:
p =
C
To determine work in joules, potential has to be in Volts, so:

Then, work is


To move a potassium ion from the exterior to the interior of the cell, it is required
J of energy.
Answer:
Part a)

Part b)
Ball thrown downwards =
Ball thrown upwards =
Part c)

Explanation:
Part a)
Since both the balls are projected with same speed in opposite directions
So here the time difference is the time for which the ball projected upward will move up and come back at the same point of projection
Afterwards the motion will be same as the first ball which is projected downwards
so here the time difference is given as



Part b)
Since the displacement in y direction for two balls is same as well as the the initial speed is also same so final speed is also same for both the balls
so it is given as




Part c)
Relative speed of two balls is given as


now the distance between two balls in 0.8 s is given as



Nuclear fusion reactions convert protons into helium; thus, becoming the source of all energy radiated by the sun.
Answer: Option D
<u>Explanation:</u>
Nuclear fusion reaction is one among the two nuclear reactions in which the atoms nucleus interact with each other to produce the products. In nuclear fusion, two smaller atoms react together to form a new atom with bigger size.
So large amount of energy is required to start the nuclear fusion reaction. The fusion reactions mostly occurs in stars. The illumination in Stars even the Sun is due to nuclear fusion reaction occurring with the atoms present in them.
Mostly the energy radiated by Sun is due to the protons-protons chain reaction. In this chain reaction, the protons get converted into helium due to nuclear fusion reaction, thus becoming the source of all energy radiated by the Sun.