Answer:
Vf = 11.04 m/s
Explanation:
First, we consider free fall motion with zero initial velocity. Using 2nd equation of motion:
h = Vi t + (1/2)gt²
where,
h = height of bridge = ?
Vi = Initial Speed = 0 m/s
t = time taken = 4.5 s
g = 9.8 m/s²
Therefore,
h = (0 m/s)(4.5 s) + (1/2)(9.8 m/s²)(4.5 s)²
Therefore,
h = 99.225 m
Now, we consider the forced motion when the youth throws the ball with some negative initial energy:
Vi = - Vi
t = 3 s
h = 99.225 m
Therefore,
99.225 m = - Vi(3 s) + (1/2)(9.8 m/s²)(3 s)²
Vi = (- 99.225 m + 44.145 m)/3 s
Vi = - 18.36 m/s
Now, we use this in 1st equation of motion for final velocity:
Vf = Vi + gt
Vf = -18.36 m/s + (9.8 m/s²)(3 s)
Therefore,
<u>Vf = 11.04 m/s</u>
Answer:
The volume occupied by fluorine gas, when the pressure is doubled and temperature is increased to 400 K is 600 ml.
Explanation:
As per ideal gas law, the pressure of any gas is inversely proportional to the volume occupied by the gas. Similarly, the volume of the gas is directly proportional to the temperature of the gas molecules. So the ideal gas equation is 
. Here P is pressure, V is volume, n is the no.of moles, R is gas constant and T is temperature.
So in this case, the fluorine gas occupies 810 mL of volume (
) at 270 K temperature (
) and pressure of about 1 atm (
). If the pressure is doubled, then the new pressure will be 
and temperature is increased to 400 K. As the no.of moles will be constant, then
Thus,
So,
Thus, the new volume occupied by fluorine gas on increase in pressure and temperature is 600 mL.
Answer:
D physiological condition
Explanation:
Sensation and perceptions are complimentary to each other but have different roles within the brain. Sensations are the process of experiencing the world with the five senses and sending that information to the brain. Perceptions are the way we interpret sensations.
D. Mechanical energy remains unchanged.
Mechanical energy = Potential energy + Kinetic energy
So if potential energy decreases, then kinetic energy must increase so that the system is balanced.
Explanation:
Electromagnetic waves are different from sound or water waves in such a way that water and sound waves are called mechanical waves that requires a material medium for their propagation.
Electromagnetic waves do no require a material medium for propagation.
- Electromagnetic waves are carried or transported by radiation and this can be passed through vacuums and different other materials.
- But mechanical waves such as water and sound waves requires a material medium for their propagation.
- They cannot pass through a vacuum.
