Because polymers are covalently bonded material, and metals are metalicly bonded material.
Covalent bonds do not let atoms exchange electrons like metalic bonds do.
You have to solve this by using the equations of motion:
u=3
v=0
s=2.5
a=?
v^2=u^2+2as
0=9+5s
Giving a=-1.8m/s^2
Then using the equation:
F=ma
F is the frictional force as there is no other force acting and its negative as its in the opposite direction to the direction of motion.
-F=25(-1.8)
F=45N
Then use the formula:
F=uR
Where u is the coefficient of friction, R is the normal force and F is the frictional force.
45=u(25g)
45=u(25*10)
Therefore, the coefficient of friction is 0.18
Hope that helps
Answer:
a) 
b) 
Explanation:
From the question we are told that:
Density 
Velocity of wind 
Dimension of rectangle:50 cm wide and 90 cm
Drag coefficient 
a)
Generally the equation for Force is mathematically given by
Therefore Torque
b)
Generally the equation for torque due to weight is mathematically given by
Where
Therefore
Answer:
= 2.33
Explanation:
.According to snell's law:
n1sin i = n2sin r ,
where n1 is refractive index of the medium in which incident ray is travelling, n2 is the refractive index of the medium in which refracted ray is travelling,
i is angle of incidence,
r is angle of refraction.
Given that,
n1 = 1,
i = 51 degrees,
r = 19.5 degrees. ,
n2= ?
So,
1*sin 51 = n2 sin 19.5
=> n2 = sin51 / sin19.5
= 2.33
1) hypothesis
2) data
3) method
I think these are correct.
