Answer:
1000 N
Explanation:
The magnitude of the electrostatic force between two charged object is given by

where
k is the Coulomb constant
q1, q2 is the magnitude of the two charges
r is the distance between the two objects
Moreover, the force is:
- Attractive if the two forces have opposite sign
- Repulsive if the two forces have same sign
In this problem:
are the two charges
r = 3000 m is their separation
Therefore, the electric force between the charges is:

For this case we first think that the skateboard and the child are one body.
We have then:
1 = jug
2 = skateboard + boy
By conservation of the linear amount of movement:
M1V1i + M2V2i = M1V1f + M2V2f
Initial rest:
v1i = v2i = 0
0 = M1V1f + M2V2f
Substituting values
0 = (7.8) (3.2) + (M2) (- 0.65)
0 = 24.96 + M2 (-0.65)
-24.96 = (-0.65) M2
M2 = (-24.96) / (- 0.65) = 38.4 kg
Then, the child's mass is:
M2 = Mskateboard + Mb
Clearing:
Mb = M2-Mskateboard
Mb = 38.4 - 1.9
Mb = 36.5 Kg
answer:
the boy's mass is 36.5 Kg
Answer:
610 meters.
Explanation:
Because Jim released the accelerator, the truck started to slow down, so the friction force will eventually stop the truck.
the kinetic energy of the truck just after Jim released the pedal is:

The work done by the friction force is given by:

The mass of Mg-24 is 24.30506 amu, it contains 12 protons and 12 neutrons.
Theoretical mass of Mg-24:
The theoretical mass of Mg-24 is:
Hydrogen atom mass = 12 × 1.00728 amu = 12.0874 amu
Neutron mass = 12 x 1.008665 amu = 12.104 amu
Theoretical mass = Hydrogen atom mass + Neutron mass = 24.1913 amu
Note that the mass defect is:
Mass defect = Actual mass - Theoretical mass : 24.30506 amu- 24.1913 amu= 0.11376 amu
Calculating the binding energy per nucleon:

So approximately 4.41294 Mev/necleon