Answer:
The work done by the steam is 213 kJ.
Explanation:
Given that,
Mass = 5 kg
Pressure = 150 kPa
Temperature = 200°C
We need to calculate the specific volume
Using formula of work done



Where,R = gas constant
T = temperature
P = pressure
=Atmosphere pressure
m = mass
Put the value into the formula


Hence, The work done by the steam is 213 kJ.
Newton's second law states that the resultant of the forces applied to an object is equal to the product between the object's mass and its acceleration:

where in our problem, m is the mass the (child+cart) and a is the acceleration of the system.
We are only concerned about what it happens on the horizontal axis, so there are two forces acting on the cart+child system: the force F of the man pushing it, and the frictional force

acting in the opposite direction. So Newton's second law can be rewritten as

or

since the frictional force is 15 N and we want to achieve an acceleration of

, we can substitute these values to find what is the force the man needs:
Answer:
2. Wavelength
Explanation:
When a photon collides with an electron and is deflected, the photon’s wavelength decreases.
When photon gained energy by the collision of the electron. Its energy and frequency will be increased and its wavelength will be decreased.
I think one hour, sorry if i'm wrong