Answer:
Latent heatnof fusion = 417.5 J
Explanation:
Specific latent heat of fusion of water is 334kJ.kg-1.
The heat required to melt water when it's ice I called latent heat because there is no temperature change, the only change observed is change in physical structure.
The amount of heat required to change 1 kg of solid to its liquid state (at its melting point) at atmospheric pressure is called Latent heat of Fusion.
Latent heat = ML
Latent heat= 1.25 kg * 334kJ.kg-1
Latent heat = 1.25*334 *(J/kg)*kg
Latent heat = 417.5 J
Answer:
<h2>E. 3.95kW</h2>
Explanation:
Power is defined as the rate of workdone.
Power = Workdone/time taken
Given Workdone = Force * distance
Power = Force * distance/time taken
Power = mgd/t (F = mg)
m = mass of the sand in kg
g = acceleration due to gravity in m/s²
d = vertical distance covered in metres
t = time taken in seconds
Given m = 2000kg, d = 12m, t = 1min = 60secs, g = 9.8m/s²
Power = 2000*9.8*12/60
Power = 3920Watts
Minimum rate of power that must be supplied to this machine is 3920Watts or 3.92kW
Answer:
86.4 hrs
Explanation:
The amount of bacteria is initially 1
It doubles every 24 hrs.
After first 24 hrs, the amount = 2
After next 24 hrs = 4
After next 24 hrs = 8
After next 24 hrs = 16
After next 24 hrs = 32
After next 24 hrs = 64
After next 24 hrs = 128
After next 24 hrs = 256
Total time taken to reach 256 = 24 x 8 = 192 hrs
For the bacteria culture on the rocket that travels at a speed of 0.893c relative to the earth, this time is contracted by the relationship
t = t'(1 - ¥^2)^0.5
Where t is the contracted time =?
t' is the time on earth
¥ = v/c
Where v is the speed of the rocket
c is the speed of light
since v = 0.893c
¥ = 0.893
Substituting, we have
t = 192 x (1 - 0.893^2)^0.5
t = 192 x 0.2025^0.5
t = 192 x 0.45 = 86.4 hrs
Answer:
11.78meters
Explanation:
Given data
Mass m = 100kg
Length of cord= 10m
Spring constant k= 35N/m
At the greatest vertical distance, the spring potential energy is equal to the gravitational potential energy
That is
Us=Ug
Us= 1/2kx^2
Ug= mgh
1/2kx^2= mgh
0.5*35*10^2= 100*9.81*h
0.5*35*100=981h
1750=981h
h= 1750/981
h= 1.78
Hence the bungee jumper will reach 1.78+10= 11.78meters below the surface of the bridge
Answer:
D) 15s
Explanation:
let Te be the period of the block-spring system on earth and Tm be the period of the same system on the moon.let g1 be the gravitational acceleration on earth and g2 be the gravitational acceleration on the moon.
the period of a pendulum is given by:
T = 2π√(L/g)
so on earth:
Te = 2π√(L/g1)
= 6s
on the moon;
Tm = 2π√(L/g2)
since g2 = 1/6 g1 then:
Tm = 2π√(L/(1/6×g1))
= √(6)×2π√(L/(g1))
and 2π√(L/(g1)) = Te = 6s
Tm = (√(6))×6 = 14.7s ≈ 15s
Therefore, the period of the block-spring system on the moon is 15s.
