Answer
given,
mass of ice hockey player = 110 Kg
initial speed of the skate = 3 m/s
final speed of the skate = 0 m/s
distance of the center of mass, m = 30 cm = 0.3 m
a) Change in kinetic energy



b) Average force must he exerted on the railing
using work energy theorem
W = Δ KE
F .d = -495
F x 0.3 = -495
F = -1650 N
the average force exerted on the railing is equal to 1650 N.
Answer:
Friction produces unnecessary heat leading to the wastage of energy. The force of friction acts in the opposite direction of motion, so friction slows down the motion of moving objects. Forest fires are caused due to the friction between tree branches. However, friction can also cause problems in a car. Friction between moving engine parts increases their temperature and causes the parts to wear down. Friction can be both harmful and helpful, so it may be necessary to decrease or increase friction.
Answer:

Explanation:
= Permittivity of free space = 
= Surface charge density = 
= 0.57-0.26
q = Charge = 
m = Mass of object = 
Electric field due to a sheet is given by

Electric field is given by

Voltage is given by

Kinetic energy is given by


The initial speed of the object is 
Well according to the molecular formula of glucose, one molecule would have 6 carbon atoms, and thus 2 molecules of glucose would have 12 carbon atoms.
The correct response would be B. 12.
Charge of electron = 1.6×10−¹⁹
(1.6×10−¹⁹)(1×10²) (2e)
= 3.2×10−¹⁷ J