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:
W = 145.8 [N]
Explanation:
To solve this problem we must remember that weight is defined as the product of mass by gravity, in this case lunar gravity.
W = m*g
where:
m = mass = 90 [kg]
g = gravity acceleration = 1.62 [kg/m²]
W = 90*1.62
W = 145.8 [N]
Answer:
Speed at which it will reach the ground is given as

Total time for which it will remain in air is given as
t = 6.3 s
Explanation:
As we know that the object is projected upwards with speed


now when it will reach the ground then we have

so we have


so we have

Now speed of the object when it reaches the ground is given as



Answer: 815.51 m
Explanation:
This situation is related to projectile motion or parabolic motion, in which the initial velocity of the bullet has only y-component, since it was fired straight up. In addition, we are dealing with constant acceleration (due gravity), therefore the following equations will be useful to solve this problem:
(1)
(2)
Where:
is the final velocity of the bullet
is the initial velocity of the bullet
is the acceleration due gravity, always directed downwards
is the time
is the vertical position of the bullet at 
Let's begin by finding
from (1):
(3)
(4)
Now we have to substitute (4) in (2):
(5)
Isolating
:
This is the displacement of the bullet after 6.9 s