Answer:
30 N
Explanation:
there are two forces act on the bar:
- weight of 1.5 kg mass, w = mg = 15 N
- weight of the bar, wb
for balance,
w * Lw = wb * Lwb
Lw = length of bar from the mass to the pivot
Lwb = lenght of bar from the center of the bar to the pivot
15 * 20 = wb * (50-20)
300 = wb * 30
wb = 300/30 = 30 N
To solve this problem we will apply the concept of Impulse. Which is described as the product between the Force and the change in time. Mathematically this can be described as

Where,
F = Force
= Time
Our values are given as,
F = 1450N

Replacing we have,


Therefore the impulse delivered to the soccer ball is
or 
According to Doppler Effect, an observer at rest will perceive a shift in the wavelength or frequency of the radiation emitted by a source in movement.This shift is given by the formula:

where:

= observed wavelength

= wavelength at rest
v = speed of source (positive if towards the observer, negative if away from the observer)
c = speed of light
Therefore, we can solve for the observed wavelength:

Substituting the given data:

= 655.80 nm
Hence, the observed wavelength of the line would be
655.80 nm. Note that this value is smaller than the one at rest, which means that we have a blue-shift, as expected for an approaching source.
ans will be 1500006.15
= 1.5*10^6
we move the decimal point to the left six digits
Answer:
Rate of heat conduction will be 935 Watt
Explanation:
We have given thickness of the floor d = 1.6 cm = 0.016 m
Area 
Temperature difference 
Thermal conductivity of the wood k = 0.200 w/M-K
We have to find heat conduction
Heat conduction is given by 
Rate of heat conduction will be 935 Watt