To solve this problem it is necessary to apply the concepts related to Newton's second law and the kinematic equations of movement description.
Newton's second law is defined as

Where,
m = mass
a = acceleration
From this equation we can figure the acceleration out, then



From the cinematic equations of motion we know that

Where,
Final velocity
Initial velocity
a = acceleration
x = displacement
There is not Final velocity and the acceleration is equal to the gravity, then





From the equation of motion where acceleration is equal to the velocity in function of time we have




Therefore the time required is 0.0705s
As per the question Bob drops the bag full with feathers from the top of the building.
The mass of the bag(m)= 1.0 lb
Let the air resistance is neglected.As the bag is under free fall ,hence the only force that acts on the bag is the force of gravity which is in vertical downward direction.
Here the acceleration produced on bag due to the free fall will be nothing else except the acceleration due to gravity i.e g =9.8 m/s^2
Here we are asked to calculate the distance travelled by the bag at the instant 1.5 s
Hence time t= 1.5 s
From equation of kinematics we know that -
S=ut + 0.5at^2 [ here S is the distance travelled]
For motion under free fall initial velocity (u)=0.
Hence S= 0×1.5+{0.5×(-9.8)×(1.5)^2}
⇒ -S =0-11.025 m
⇒ S= 11.025 m
=11 m
Here the negative sign is taken only due to the vertical downward motion of the body .we may take is positive depending on our frame of reference .
Hence the correct option is B.
-3 m/s
---------
per min
oh I think 8m/s to 3m/s to 0m/s
idk probably -0.08
<h3><u>Answer;</u></h3>
<em>B. Sound waves can move through various mediums.</em>
<h3><u>Explanation;</u></h3>
- <em><u>A wave is a transmission of a disturbance from one point to another</u></em>. It involves transmission of energy from the source to another point.
- <u><em>A wave may or may not require a medium for transmission.</em></u> Waves that require medium for transmission are called <em><u>mechanical waves </u></em>and those that do not require medium for transmission are known as <em><u>electromagnetic waves</u></em>.
- <em><u>Light is an example of electromagnetic wave therefore it can be blocked when obstacles are placed on its path.</u></em> However, for the case of sound waves, they can not be blocked by an obstacle as sound would travel through the medium used to block.
Answer:
De Broglie wavelength of the bullet is given as

Explanation:
As per De Broglie hypothesis we know that the wavelength of De Broglie waves is the ratio of Plank's constant and momentum of the particle
here we know that the bullet mass is
m = 0.075 kg
speed of the bullet is given as
v = 350 m/s
Now we have


Now we know that


