Answer:
yes, 800 has 1 significant digit
neither leading zero nor trelling zero are significant figure except when there's a decimal point
Answer:
e). 
Explanation:
As we know that wheel is turned by 90 degree angle
so the angular speed of the wheel is given as

now we have


now the centripetal acceleration of the point P is given as



tangential acceleration is given as



now net acceleration is given as



thats how it works and thanks for points
Answer:
so his far point according to this pair of glass is 200 cm
Explanation:
power of old pair of corrective glasses is given as

now we have



now we know that for normal vision the maximum distance of vision is for infinite distance
so by lens formula we have



so his far point according to this pair of glass is 200 cm
Answer:

Explanation:
using the law of the conservation of energy:


where K is the spring constant, x is the spring compression, N is the normal force of the block,
is the coefficiet of kinetic friction and d is the distance.
Also, by laws of newton, N is calculated by:
N = mg
N = 3.35 kg * 9.81 m/s
N = 32.8635
So, Replacing values on the first equation, we get:

solving for
:
