55 J
Explanation:
Kinetic energy is given as: 0.5MV^2 where M is the mass and V is the speed of rotation. Since the masses are point masses, we calculate the point mass for each mass.
M1 = 30*0.2^2 = 1.2kgm^2
M2 = 20*0.4^2 = 3.2kgm^2
V = 5 rad/s
Calculating using the formula above, we obtain :
0.5(1.2+3.2)5^2 =0.5*4.4*25 = 55 J
Units of impulse: N • s, kg • meters per second
Explanation:
Impulse is defined in two ways:
1)
Impulse is defined as the product between the force exerted in a collision and the duration of the collision:

where
F is the force
is the time interval
Since the force is measured in Newtons (N) and the time is measured in seconds (s), the units for the impulse are
![[I] = [N][s]](https://tex.z-dn.net/?f=%5BI%5D%20%3D%20%5BN%5D%5Bs%5D)
So,
N • s
2)
Impulse is also defined as the change in momentum experienced by an object:

where the change in momentum is given by

where m is the mass and
is the change in velocity.
The mass is measured in kilograms (kg) while the change in velocity is measured in metres per second (m/s), therefore the units for impulse are
![[I]=[kg][m/s]](https://tex.z-dn.net/?f=%5BI%5D%3D%5Bkg%5D%5Bm%2Fs%5D)
so,
kg • meters per second
Learn more about impulse:
brainly.com/question/9484203
#LearnwithBrainly
Answer:
The magnitude of the magnetic force acting on the wire is zero, because the magnetic field is parallel to the wire.
In fact, the magnetic force exerted by the magnetic field on the wire is
where I is the current in the wire, L the length of the wire, B the magnetic field intensity and the angle between the direction of B and the wire. In our problem, B and the wire are parallel, so the angle is and so , therefore the magnetic force is zero: F=0.
Answer:
1, 2, 4, 5 are correct
Explanation:
1) This is true because In a neutral atom, the number of positive charges (protons) is equal to the number of negative charges (electrons).
2) This is true because the mass of the atom which is made up of the protons and neutrons, is located in the tiny nucleus.
3) This is not true because the positively charged particles in the nucleus are called protons.
4) This is true because electrons move around the nucleus in diffuse areas known as orbitals.
5) This is true because opposite charges attract each other. And electron is a negative charge.
6) This is not true because the radius of the electron cloud is normally 10,000 times larger than the radius of the nucleus.
V^2=u^2+2as
V=0
a =-u^2/2s
a=[4]^2/2[4]
a=-2m/s^2