Answer:

Explanation:
The acceleration of the bycicle is given by:

where
v = 20 m/s is the final velocity of the bike
u = 40 m/s is the initial velocity
t = 5 s is the time interval
Substituting numbers, we find

and the acceleration is negative, which means that the bycicle is slowing down.
Explanation:
Law of conservation of momentum states that in an isolated system when two objects collide with each other then total momentum before and after the collision is equal.
Thus, we can conclude that the law of conservation of momentum states that the total momentum of interacting objects does not change. This means the total momentum before a collision or explosion is equal to the to momentum after a collision or explosion.
Answer:
Normal Force is usually perpendicular to the movement and static friction usually means that there is no movement.
Explanation:
The work donde by any force on an object is equal to the displacement of the object multiplied by the component of the force that is in the direction of the displacement.
Normal force is usually perpendicular to the movement, so there is no component in the direction of the displacement. This is why it is zero in most circumstances.
<em>Static</em> friction on the other hand, usually means that there is no movement at all (it's static). It means that there is no displacement between the object and ground (in most cases). If there is no displacement, there is no work.
Electrical energy is used to run the fan
Here as per given condition 750 J of electrical energy is used to run the fan which is converted into Kinetic energy as 400 J
So here we can see that 350 J of energy is lost against many other type of frictional and resistive loses.
So here we can say that out of 750 J of energy only 400 J is used to run the fan and rest amount of energy is lost against friction.
also we can say that efficiency of this fan will be



Answer:
true
Explanation:
Newton is the measure of the force with turns to be gravity multiplying the mass. Thus, the forces acts on the particles in the direction of the movement of the particles