Answer:
I=2 kg.m/s
Explanation:
The impulse is defined as the change of momentum:
![I=p_f-p_o\\I=m*v_f-m*v_o\\I=0.02kg*[(-60m/s)-40m/s]\\I=2kg.m/s](https://tex.z-dn.net/?f=I%3Dp_f-p_o%5C%5CI%3Dm%2Av_f-m%2Av_o%5C%5CI%3D0.02kg%2A%5B%28-60m%2Fs%29-40m%2Fs%5D%5C%5CI%3D2kg.m%2Fs)
We took the final velocity as negative since it is going on the opposite direction of the intial motion of the ball.
Answer:
d) The stone will have about 50 joules of kinetic energy and 0 joules of potential energy .
Explanation:
Given :
Initial Potential energy , 
.
Initial Kinetic energy , 
. ( because ball is in rest )
Now , we know , kinetic energy is maximum when an object reaches ground .
Also , potential energy is zero when an object is in ground .
We know , by conservation of energy :
Initial total energy = Final total energy
Therefore , option d) is correct .
A child slides down a hill on a toboggan with acceleration of 1.8 m/s2. if she starts from rest, how far has she traveled in: 2 seconds
Answer:
2.4 m
Explanation:
From the question above,
Applying equation of motion,
s = ut+at²/2....................... Equation 1
Where t = time, u = initial velocity, a = acceleration, s = distance.
make s the subject of the equation,
Given: a = 1.8 m/s², t = 2 seconds, u = 0 m/s (from rest)
Substitute these value into equation 1
s = 0(2)+1.8(2²)/2
s = 1.2(4)/2
s = 2.4 m.
Hence she has traveled 2.4 m
To be sure that the color is due to sodium, do a
flame test. This is used to identify the presence of small number of metal ions
in a compound. For sodium, the brilliant color of bright yellow is a result of
an excited electron in a very high level of energy and fall to a lower level called
the ground state.
In
addition, metals have different jump sizes in the energy level and
this means that each different metal will have a different pattern of spectral
lines, which results to different flame color.
