#1
Volume of lead = 100 cm^3
density of lead = 11.34 g/cm^3
mass of the lead piece = density * volume


so its weight in air will be given as

now the buoyant force on the lead is given by


now as we know that


so by solving it we got
V = 11.22 cm^3
(ii) this volume of water will weigh same as the buoyant force so it is 0.11 N
(iii) Buoyant force = 0.11 N
(iv)since the density of lead block is more than density of water so it will sink inside the water
#2
buoyant force on the lead block is balancing the weight of it




(ii) So this volume of mercury will weigh same as buoyant force and since block is floating here inside mercury so it is same as its weight = 11.11 N
(iii) Buoyant force = 11.11 N
(iv) since the density of lead is less than the density of mercury so it will float inside mercury
#3
Yes, if object density is less than the density of liquid then it will float otherwise it will sink inside the liquid
Answer:
6.78 X 10³ N/C
Explanation:
Electric field near a charged infinite plate
= surface charge density / 2ε₀
Field will be perpendicular to the surface of the plate for both the charge density and direction of field will be same so they will add up.
Field due to charge density of +95.0 nC/m2
E₁ = 95 x 10⁻⁹ / 2 ε₀
Field due to charge density of -25.0 nC/m2
E₂ = 25 x 10⁻⁹ / 2ε₀
Total field
E = E₁ + E₂
= 95 x 10⁻⁹ / 2 ε₀ + 25 x 10⁻⁹ / 2ε₀
= 6.78 X 10³ N/C
Answer:
c
Explanation:
If you double your speed, the energy dissipated in a crash is four times greater
Because impact increases with square of increase in speed.
- The horizontal pushing force required to just start the crate moving is 447 N.
- The horizontal pushing force required to slide the crate across the dock at a constant speed is 241 N.
<u>Explanation</u>:
- By the definition of the coefficient of static friction we have:
μ
=
,
where,
is the horizontal pushing force,
W = mg is the weight of the crate directed downward,
is the static friction force-directed opposite to the horizontal pushing force and equal to it,
N is the force of reaction directed upward and equal to the weight of the crate.
From this formula we can find the horizontal pushing force required to just start the crate moving:
= 0.760
60 kg
9.8 m / s^2
= 447 N.
- By the definition of the coefficient of kinetic friction we have:
u
,
where,
is the horizontal pushing force,
W = mg is the weight of the crate directed downward,
is the kinetic friction force-directed opposite to the horizontal pushing force and equal to it,
N is the force of reaction directed upward and equal to the weight of the crate.
From this formula we can find the horizontal pushing force required to slide the crate across the dock at a constant speed:
= 0.410
60
9.8
= 241 N.
- The horizontal pushing force required to just start the crate moving is 447 N.
- The horizontal pushing force required to slide the crate across the dock at a constant speed is 241 N.
Answer:
Temperature of the sink will be 191.1 K
Explanation:
We have given that heat withdrawn form the source = 10 KJ
Work done = 3 KJ
We know that efficiency is given by

Higher temperature is given by 
We have to find the lower temperature 
We know that efficiency is also given by

So 
So temperature of the sink will be 191.1 K