Answer:
9.8m/s²
Explanation:
The acceleration of the ball thrown after leaving my hand is 9.8m/s². This will be the acceleration due to gravity on the body.
- Acceleration due to gravity is caused by the pull of the earth on a massive object.
- The value of this acceleration is 9.8m/s².
- As the ball nears the surface, it comes near zero.
Answer:
1. all of them
2. cork and wax
3. iron, lead, and aluminum
4. none of them
Explanation:
1.Which material will displace a volume of water? all of them
When an object is introduced into a container with a volume of water, a volume of liquid equal to the volume of the object is displaced
2.Which material will displace a volume of water less than its own volume?
cork and wax
because the density of the object is less than that of the displaced liquid
3.Which material will displace a volume of water equal to its own volume?
iron, lead, and aluminum
because Arquimedes's principle: any body plunged inside a fluid in this case water experiences an ascending force called push, equivalent to the weight of the fluid removed by the body
4.Which material will displace a volume of water greater than its own volume?
None of them
Answer:
a) P=0.25x10^-7
b) R=B*N2*E
c) N=1.33x10^9 photons
Explanation:
a) the spontaneous emission rate is equal to:
1/tsp=1/3 ms
the stimulated emission rate is equal to:
pst=(N*C*o(v))/V
where
o(v)=((λ^2*A)/(8*π*u^2))g(v)
g(v)=2/(π*deltav)
o(v)=(λ^2)/(4*π*tp*deltav)
Replacing values:
o(v)=0.7^2/(4*π*3*50)=8.3x10^-19 cm^2
the probability is equal to:
P=(1000*3x10^10*8.3x10^-19)/(100)=0.25x10^-7
b) the rate of decay is equal to:
R=B*N2*E, where B is the Einstein´s coefficient and E is the energy system
c) the number of photons is equal to:
N=(1/tsp)*(V/C*o)
Replacing:
N=100/(3*3x10^10*8.3x10^-19)
N=1.33x10^9 photons
The correct answer for this question is "Two-car length rule." While driving, the principle that you should be used to keep the appropriate distance between your vehicle and the vehicle in front of you is to follow the <span>Two-car length rule. This rule is to be followed for safety.</span>
