Physical changes are those change which just externally or physically change the state of the object . for example : water boils and evaporates... here the state is just changing from liquid to vapour while the composition is the same.
chemical changes are those which bring about a change in the composition of a substance. for example: burning of paper changes into ash .
Answer:
1. Unit for work is measured in Joules.
Formula for work is power * time taken
2 The unit for force is Newton
A work done in lifting a jar of water
3. The unit for measuring power is Joules.
The formula for measuring power is work done/time taken
We know, weight = mass * gravity
10 = m * 9.8
m = 10/9.8 = 1.02 Kg
Now, Let, the gravity of that planet = g'
g' = m/r² [m,r = mass & radius of that planet ]
g' = M/10 / (1/2R)² [M, R = mass & radius of Earth ]
g' = 4M / 10R²
g' = 2/5 * M/R²
g' = 2/5 * g
g' = 2/5 * 9.8
g' = 3.92
Weight on that planet = planet's gravity * mass
W' = 3.92 * 1.02
W' = 4 N
In short, Your Answer would be 4 Newtons
Hope this helps!
Answer:

Explanation:
As we know that the speed of the sound is given as

now at t = 273 k = 0 degree

so we have


now when temperature is changed to 313 K we have

now we have



now from two equations we have

so we have


Length of the pipe = 0.39 m
Number of harmonics = 3
Now there are 3 loops so here we can say


now here at the center of the pipe it will form Node
we need to find the distance of nearest antinode
So distance between node and its nearest antinode will be


So the distance will be 6.5 cm