Answer:
Explanation:
<u>Density </u>
The density of a substance is the mass per unit volume. The density varies with temperature and pressure.
The formula to calculate the density of a substance of mass (m) and volume (V) is:
The cube has a mass of m=3.75 g and a volume of V=3 ml, thus the density is:
Since 1 kg=1000 mg and 1 lt = 1000 ml, the density has the same value but with different units:
Answer:
a) 4.2m/s
b) 5.0m/s
Explanation:
This problem is solved using the principle of conservation of linear momentum which states that in a closed system of colliding bodies, the sum of the total momenta before collision is equal to the sum of the total momenta after collision.
The problem is also an illustration of elastic collision where there is no loss in kinetic energy.
Equation (1) is a mathematical representation of the the principle of conservation of linear momentum for two colliding bodies of masses and
whose respective velocities before collision are
and
;
where and
are their respective velocities after collision.
Given;
Note that =0 because the second mass
was at rest before the collision.
Also, since the two masses are equal, we can say that so that equation (1) is reduced as follows;
m cancels out of both sides of equation (2), and we obtain the following;
a) When , we obtain the following by equation(3)
b) As stops moving
, therefore,