I'm going to assume that this gripping drama takes place on planet Earth, where the acceleration of gravity is 9.8 m/s². The solutions would be completely different if the same scenario were to play out in other places.
A ball is thrown upward with a speed of 40 m/s. Gravity decreases its upward speed (increases its downward speed) by 9.8 m/s every second.
So, the ball reaches its highest point after (40 m/s)/(9.8 m/s²) = <em>4.08 seconds</em>. At that point, it runs out of upward gas, and begins falling.
Just like so many other aspects of life, the downward fall is an exact "mirror image" of the upward trip. After another 4.08 seconds, the ball has returned to the height of the hand which flung it. In total, the ball is in the air for <em>8.16 seconds</em> up and down.
Answer:
The battery can supply 130 W for 11.75 h
Explanation:
In order to discover the time in wich the battery can supply this energy we need to find how much current is being drawn from it, we do that by using the equation for real power that is P = V*I, since we have V and P we can solve for I as seen bellow:
I = P/V = 130/12 = 10.834 A
We can use this value to find how many hours the power can supply said current. We do that by dividing the current capacity of the battery by the current drawn:
t = 141/12 = 11.75 h
Answer:
A) 
B) 
C) 
Explanation:
Given:
- mass of flywheel,
- diameter of flywheel,
- rotational speed of flywheel,
- duration for which the power is off,
- no. of revolutions made during the power is off,
<u>Using equation of motion:</u>
Negative sign denotes deceleration.
A)
Now using the equation:
is the angular velocity of the flywheel when the power comes back.
B)
Here:
Now using the equation:
is the time after which the flywheel stops.
C)
Using the equation of motion:
revolutions are made before stopping.
Answer
Given,
refractive index of film, n = 1.6
refractive index of air, n' = 1
angle of incidence, i = 35°
angle of refraction, r = ?
Using Snell's law
n' sin i = n sin r
1 x sin 35° = 1.6 x sin r
r = 21°
Angle of refraction is equal to 21°.
Now,
distance at which refractive angle comes out
d = 2.5 mm
α be the angle with horizontal surface and incident ray.
α = 90°-21° = 69°
t be the thickness of the film.
So,
t = 2.26 mm
Hence, the thickness of the film is equal to 2.26 mm.
