Answer:
7.2g
Explanation:
From the expression of latent heat of steam, we have
Heat supplied by steam = Heat gain water + Heat gain by calorimeter
mathematically,
+ 
=
+
L=specific latent heat of water(steam)=2268J/g
=specific heat capacity=4.2J/gK
=specific heat capacity of calorimeter =0.9J/gk
=280g
=38g
α=change in temperature
=(40-25)=15
=(40-25)=15
=(100-40)=60
Note: the temperature of the calorimeter is the temperature of it content.
From the equation, we can make 
the subject of formula
Hence
Hence the amount of steam needed is 7.2g
Answer:
I think it's 2 the photo is hard to tell what they are exactly talking about.
Answer:
v = 3.00 x 10⁸ m/s
Explanation:
given,
speed of light in vacuum = 299,792,458 m/s
speed of light in scientific notation to three significant figures
v = 2.99792458 x 10⁸ m/s
by rounding off the speed to three significant figure.
v = 3.00 x 10⁸ m/s
On the fourth place the value is greater than 5 so, on the third place 1 will be added.
now, the speed with three significant figure comes out to be
v = 3.00 x 10⁸ m/s
<span>The blades should turn in two directions.</span>
Answer
Assuming the mass of the car, m = 43000 kg
initial speed u = 0
vertical distance moved, h = 8.8 m
spring constant k = 5 x 10⁵ N / m
acceleration of gravity = 9.8 m/s²
From law of conservation of energy ,
Gravitational potential energy at starting position =potential energy of the spring at maximum compression
x = 14.83 m
If the mass of the car is equal to 43000 Kg the spring is compressed to 14.83 m
