Answer:
Explanation:
A component of 150 N in vertical direction will reduce the magnitude of reaction force.
reaction force exerted by the floor
= mg - 150 sin 30
where m is mass of the crate .
the magnitude of the horizontal component of the 150-newton force
150 cos30
= 130 N
This force tries to pull the crate in forward direction with acceleration but it has no acceleration . It is so because frictional force of equal magnitude acts on it in opposite direction which makes the net force acting on it equal to zero.
Hence frictional force is equal to 150 cos 30.
= 130 N .
Answer:
Exothermic reactions increase the entropy of the surroundings. Simply put, entropy measures the dispersal of energy. Since ΔH is negative in an exothermic reaction, this must mean that ΔS will take on a positive value, indicating an increase in entropy.
Answer:
t = 96.1 nm
Explanation:
For strong reflection through liquid layer we know that the path difference between two reflected light rays must be integral multiple of wavelength
now we know that the path difference of two reflected light from thin liquid layer is given as
here we know that
t = thickness of layer
N = 0 (for minimum thickness of layer)
now we have
Answer:
Explanation:18kt alloy contains
i) 75% of gold
rhogold=19.3g/cm^3
=75/100×19.3
=14.475g/cm^3
ii) 16% of silver
rhosilver=10.5g/cm^3
=16/100×10.5
=1.68g/cm^3
iii) 9% of copper
rhocopper =8.90g/cm^3
=9/100×8.9
=0.801g/cm^3
Overall density of 18kt gold
=(0.801+1.68+14.475)g/cm^3
=16.956g/cm^3
=17g/cm^3 to 3s.f
Answer:
I reckon towards b. Let me know if im right
