Answer:
Explanation:
Given
mass of book(m)=2.1 kg
height up to which book is lifted is (h)2.2 m
height of person 
Potential energy of book relative to ground=mgh

(b)PE w.r.t to person head =mg(h-h0)

work done by person in lifting box 2.2 m w.r.t floor
Word done =Potential Energy of box relative to floor=45.2 J
Answer:
a) 
b) 
Explanation:
From the question we are told that:
Velocity 
Time 
a)
Generally From Newton's motion equation for Average acceleration is mathematically given by

Since its from Rest Therefore



b)
Generally the equation for Average Velocity is mathematically given by







Answer: Descomponiendo los ingresos de Brasil, encontramos que se derivan de los siguientes tres sectores: agricultura, industria y servicios. Según estimaciones de 2014, el 5,8% de los ingresos de Brasil provino de la agricultura, el 23,8% de la industria y el 70,4% de los servicios.Durante las décadas de 1940 y 1950, el gobierno brasileño comenzó a construir acerías, refinerías de petróleo y represas hidroeléctricas. ... Brasil se encuentra entre las principales naciones industriales del mundo, debido al gasohol.
Explanation:
Answer:
Explanation:
If you drop a ball from
the top of a building it
gains speed as it falls.
• Every second, its
speed increases by
10 m/s.
• Also it does not fall
equal distances in
equal time intervals
• If the acceleration = 0 then the velocity is
constant. [remember that acceleration is
the rate of change of velocity]
• In this case the distance an object will
travel in a certain amount of time is given
by distance = velocity x time
• For example, if you drive at 60 mph for
one hour you go 60 mph x 1 hr = 60 mi.