The first law of thermodynamics says that the variation of internal energy of a system is given by:

where Q is the heat delivered by the system, while W is the work done on the system.
We must be careful with the signs here. The sign convention generally used is:
Q positive = Q absorbed by the system
Q negative = Q delivered by the system
W positive = W done on the system
W negative = W done by the system
So, in our problem, the heat is negative because it is releaed by the system:
Q=-1275 J
while the work is positive because it is performed by the surrounding on the system:
W=+855 J
So, the variation of internal energy of the system is
<span>50 N
The centripetal force upon an object is expressed as
F = mv^2/r
So let's substitute the known values and calculate
F = mv^2/r
F = 1.0 kg * (5.0 m/s)^2 / 0.5 m
F = 1.0 kg * 25 m^2/s^2 / 0.5 m
F = 25 kg*m^2/s^2 / 0.5 m
F = 50 kg*m/s^2
F = 50 N
So the answer is 50 N which matches one of the available choices.</span>
The resultant force on the animal = Resultant mass * total acceleration
F = 0.2 * 2.5 to the right
F = 0.5 to the right.
As, girl exerting a force of 3.5 N & it's not mentioned that she is in right or left, so the force exerting by boy would be either:
3.5-0.5 = 3 OR 3.5+0.5 = 4
If boy exerting a greater force then, answer will be 4 N & if girl exerting a greater force the, answer will be 3 N
Hope this helps!
Reactant is<span> a substance that is in a chemical </span>reaction<span>. Product is a substance that is produced by the chemical </span>reaction. A chemical change that you are familiar with isrust<span>. In this chemical </span>reaction<span>, </span>oxygen<span> and </span>iron<span>, which are the </span>reactants,combine to form<span> a product called </span>iron oxide(rust<span>)
(Mark me as brainiest, vote, and give thanks! Trying to rank up!)</span>
Answer:
Each half of the force pair acts on a different object.
Explanation:
When a tennis racket strikes a tennis ball a pair force is produced. when the racket strikes the ball the racket exerts an action force on the tennis ball, according to Newton's third law for every action there is an equal and opposite reaction force, as a reaction the ball exert an equal and opposite force on the racket. These forces are often called pair forces.
As the forces acts on different bodies (Action force act on ball and reaction force act on racket) so the net force tennis ball is never zero.