Answer:
Part A
Newton's 3rd law states that action and reaction are equal and opposite, mathematically, we have;
= -
Where;
= The action force
= The reaction force
Part B
The law indicates that the force with which a rocket ship uses in taking off from the Earth,
is equal in magnitude, and opposite in direction to the reaction force of the Earth to the motion of the rocket, (-)
Part C
The law is a universal law, and it will also affect the rocket ship in space, as the force of the jet from the exhaust is directed towards Earth while in space, the rocket is propelled deeper into space
Explanation:
The topic here is momentum.
When a collision is said to be elastic, it means that the colliding objects now travel at their own new, indivual and distinct velocities, often in different directions.
So we write that as,
(mass of football player x velocity of football player) + (mass of referee x velocity of referee) = (mass of football player x velocity of football player) + (mass of referee x velocity of referee)
(M × 8) + (80 × 0) = (M× 0) + (80 × 5)
8M = 400
M = 50 kg
Speed is scalar, meaning it's only going to be like 74 mph, doesn't matter which direction. Velocity is a vector, meaning it has direction. You can go -74mph when talking about velocity, not speed.
Answer:
The time interval is 22.76 hr.
Explanation:
Given that,
Time = 30 hrs
Speed = 0.74c
We need to calculate the time interval measured in earth frame
Using formula of time dilation

Where,
= time interval measured in earth frame
=proper time interval
Put the value into the formula




We need to calculate the proper time interval when the velocity is 0.86c
Using formula of time dilation



Hence, The time interval is 22.76 hr.
Answer:
Instantaneous speed means speed at any instant
that means Speed is changing with time
You know speed is distance/time
So that means distance is also changing with time
So we take infinitesimal small distance per infinitesimal small time As we assume speed is constant in infinitesimal small time dt
So, we take speed = ds/dt
ds = infinitesimal small distance
dt = infinitesimal small time
As its ratio is equal to speed at any instant
Note : We are taking infinitesimal small distance
But :) we are taking infinitesimal small time also
As you know if denominator is small fraction is large So fraction always give large value
So it's not O ( this makes confuse to most of students)
So, thanks
Good question
Keep thinking like this :)