Question

hi guys!!! happy Janmashtami please help me with these questions from 1 to 4

Answer 1

1) third one is not the unit of velocity
2) The retardation of the body is the negative acceleration that is 2.5 m/s and it is also known as deceleration.
3) Since steel has the highest density the steel solid has the highest mass and therefore the most inertia.
4) (i) due to lack of friction
(ii)An object undergoing uniform circular motion is moving with a constant speed. Nonetheless, it is accelerating due to its change in direction.
(iii) because it applies a large amount of pressure on the hose

Answer 2

First Of All HAPPY JANMASTHMI..... Bolo Raadhe Raadhe .. :D

Coming To Your Questions...

1) The Third One $m^{-1} s$ is not correct... If You go through the formula of Velocity.. It is Displacement/Time ... or m/s or $\frac{m}{s}$ or $ms^{-1}$.. So Third one is not correct

2) Retardation Means.. Going in Opposite Direction of its motion... Means If you have seen a car Taking Reverse or Coming Backward .. That is what Retardation is...

It's unit is same as Acceleration but a minus same in front of that when you solve numericals ..

However it's unit is : metre per second square $m/s^{2}$

3) It's Steel.. Because Inertia ∝ Mass.. And Here Density of Steel is Highest among them..

4) a)  It becomes Difficult Because.. We can Walk Because an Opposite force that is FRICTION is acting on us.. But in the slippery surface FRICTION is very less.. Hence It is hard to walk on that...

b) In Circular Motion.. Speed can be Constant.. But Velocity and  Acceleration can't be uniform.. Because they are Vector Quantity and In Circular Motion Direction Changes in every single second.. Hence It's not constant.. So you can say it Accelerated..

c) According to Newton's Third Law.. Every Performed action has Equal and Opposite reaction..

When a Fireman holds the Hose.. The Force coming from That hose is very high.. And due to Third Law of Motion.. Fireman also experience that Force.. Hence they Find it Difficult..