As per the question the length of the string is given as 2 metre.
A ball is attached to the string.
The ball is taken above the head and the ball starts swinging.
Swinging motion of a body may be oscillatory or circular. Here the motion is circular.
Here the length of the string will be considered as the radius of the circular path. we are asked to calculate the distance traveled by the ball in each circular rotation.
As the motion is circular, the path covered by the ball in each rotation will be equal to the circumference of the circle.
The circumference of the circle is given as
where C is the circumference.
hence C=2×3.14×2 metre
=.12.56 metre.
Hence distance covered by the ball in each circular rotation is 12.56 metre.
Here the displacement is zero. one should not be confused between distance and displacement.
The change in momentum of the ball is D) 1.8 kg m/s
Explanation:
The change in momentum of the ball is given by:
where
m is the mass of the ball
v is the final velocity
u is the initial velocity
In order to calculate the change in momentum correctly, we have to correctly take into account the sign of the velocity. Taking the final direction of the ball as positive direction, we have:
u = -12 m/s is the initial velocity
v = +18 m/s is the final velocity (it changes sign because the direction has changed)
m = 0.060 kg is the mass of the ball
Solving the equation, we find the change in momentum of the ball:
Learn more about change in momentum:
brainly.com/question/9484203
#LearnwithBrainly
There is 0 acceleration because the pony is moving at a constant velocity
Answer: send the message underwater because a more dense medium would make the sound travel faster.
Explanation:
Dolphins communicate using compression waves - longitudinal waves. Longitudinal waves requires a medium to travel. A longitudinal wave transfers energy by the vibration of medium particles in the direction of the wave motion. Compression are the regions where density of the medium is higher and rarefaction is a low density region.
A longitudinal wave travels faster in a denser medium. It has maximum speed in solid and minimum in gas. Thus, to transfer message quickly to dolphin B., dolphin A should send the message underwater and not in air. This is because water has higher density than air. Molecules collide more quickly in water than in air and it takes less time for signal to travel.
Energy of electron in atom level n =
When n = 4
When n = 5
Energy of photon absorbed = -0.544 - (-0.85) = 0.306 eV = 0.489 * J
We also have energy of photon =
Comparing both
So, Energy of photon = 4069 nm