<span>Last choice on the list:
Object A has a net charge of 0 because the positive and negative
charges are balanced.
Object B has a net charge of –2 because there is an imbalance of
charged particles (2 more negative electrons than positive protons).</span>
Answer:
3 significant figures
Explanation:
here zero is counted as one of the significant figures since it lies next to an integer.
hence the number has 3 sfg
To solve this problem, we will get f and then we will use it to calculate the power.
So, for this farsighted person,
do = 25 cm and di = -80
Therefore:
1/f = (1/25) + (1/-80) = 0.00275 = 0.275 m
Power = 1/f = 1/0.275 = +3.6363 Diopeters.
This means that the lens is converging.
Answer:
(a) They must have same direction
(b) It is not necessary for them to have same magnitudes
Explanation:
(a)
Momentum is a vector quantity. It is the product of mass (scalar) and velocity (vector). Thus, if the direction of velocity is changed, then as a result the direction of momentum will also change or its magnitude or component in the same direction will change. Hence, for the two objects to have same momentum, the directions of their velocities must also be the same.
(b)
Since, the momentum is product of velocity and mass. It is possible that two bodies of different masses with different velocities might have same momentum, provided the direction of their velocities is same.
For example, take a body of mass 4 kg moving with speed 5 m/s. It will have a momentum of 20 N.s. Now, consider another body of mass 2 kg, moving with speed 10 m/s. It will also have a momentum of 20 N.s.
Thus, it is not necessary for two objects to have same magnitude of velocity to have same momentum.
