Answer:
I. Speed = 20m/s
II. Velocity = 20m/s due North.
Explanation:
<u>Given the following data;</u>
Distance = 40m
Time = 2secs
To find the speed;
Mathematically, speed is given by the formula;

Substituting into the equation, we have;

<em>Speed = 20m/s.</em>
In physics, we use the same formula for calculating speed and velocity. The only difference is that speed is a scalar quantity and as such has magnitude but no direction while velocity is a vector quantity and as such it has both magnitude and direction.

<em>Therefore, the velocity is 20m/s due North</em>.
Answer:
1/2mv^2 a(7.5 b(15 kg c(60 kg d(120 kg. nevermind i found the answer its (15 kg) because to solve for m its m= K2/v squared.
Explanation:
Here it is an application of Newton's III law
as we know by Newton's III law that every action has equal and opposite reaction
So here as we know that two boys jumps off the boat with different forces
from front side of the boat the boy jumps off with force 45 N which means as per Newton's III law if boy has a force of 45 N in forward direction then he must apply a reaction force on the boat in reverse direction of same magnitude
So boat must have an opposite force on front end with magnitude 45 N
Now similar way we can say
from back side of the boat the boy jumps off with force 60 N which means as per Newton's III law if boy has a force of 60 N in backward direction then he must apply a reaction force on the boat in reverse direction of same magnitude
So boat must have an opposite force on front end with magnitude 60 N
So here net force due to both jump on the boat is given by



so boat will have net force F = 15 N in forward direction due to both jumps
Answer:
D. Molecules of a gas slow down and change to a liquid state.
Explanation:
- Condensation refers to a process by which a gas changes from gaseous state to liquid state. For example, water vapor changes to from the state of being a gas to liquid state water.
- Condensation is the opposite of evaporation and occurs when gaseous particles slow down and change into liquid state.
- Heat energy is lost during condensation and gaseous molecules lose kinetic energy making them to slow down and thus changing to liquid state,