Answer:
t = 0.029s
Explanation:
In order to calculate the interaction time at the moment of catching the ball, you take into account that the force exerted on an object is also given by the change, on time, of its linear momentum:
(1)
m: mass of the water balloon = 1.20kg
Δv: change in the speed of the balloon = v2 - v1
v2: final speed = 0m/s (the balloon stops in my hands)
v1: initial speed = 13.0m/s
Δt: interaction time = ?
The water balloon brakes if the force is more than 530N. You solve the equation (1) for Δt and replace the values of the other parameters:
The interaction time to avoid that the water balloon breaks is 0.029s
Where danger is and how to avoid it as well as to locate other whales
Light that enters the new medium <em>perpendicular to the surface</em> keeps sailing straight through the new medium unrefracted (in the same direction).
Perpendicular to the surface is the "normal" to the surface. So the angle of incidence (angle between the laser and the normal) is zero, and the law of refraction (just like the law of reflection) predicts an angle of zero between the normal and the refracted (or the reflected) beam.
Moral of the story: If you want your laser to keep going in the same direction after it enters the water, or to bounce back in the same direction it came from when it hits the mirror, then shoot it <em>straight on</em> to the surface, perpendicular to it.
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.
