Answer:
The velocity of the first block is 1.15m/s while of the second block 2.56m/s.
Explanation:
Momentum is only conserved in an isolated system, and because this problem requires us to find the value of the two variables, we need two equations; therefore, to conserved momentum the energy must be released in to the system only after the collision has occurred.
Therefore, from conservation of momentum



and from conservation of energy



Thus, we have two equations and two unknowns


which has solutions
and

Since the blocks cannot pass through each other, the 0.5kg block cannot have
(moves to the left) while the 0.4 kg block has
(moves to the right); therefore, we take the first solution for the velocities:
.
Thus , the velocity of the first block is 1.15m/s while of the second block 2.56m/s.
Rocket thrust equation
= ( mass flow rate of fuel burnt ) X (Velocity of gas ejected ) + ( Exit Pressure - Outdoor Pressure ) X ( Area of exhaust )
In this case, we can assume the exit pressure = outdoor pressure and since area of exhaust is not given, it can be assumed to be negligible.
In this case, by Newton 3rd’s law,
Force exerted by gas on rocket
= Force exerted by rocket on gas
= (10kg/s) X (5 x 10^3 m/s)
= 5 x 10^4 N
Answer:
If you know that that free fall acceleration g on the Moon is about 6 times less than on the Earth, it gives you the answer: on the Moon the same pendulum will have a period about √6≈2.45 longer than on the Earth.
Answer:
0.256 hours
Explanation:
<u>Vectors in the plane
</u>
We know Office A is walking at 5 mph directly south. Let
be its distance. In t hours he has walked

Office B is walking at 6 mph directly west. In t hours his distance is

Since both directions are 90 degrees apart, the distance between them is the hypotenuse of a triangle which sides are the distances of each office



This distance is known to be 2 miles, so


t is approximately 15 minutes
Answer:
The average velocity is 180 km/hr
Explanation:
Given;
initial velocity, u = 60 km per hour
final velocity, v = 120 km per hour
initial time = 1 hour
final time = 2 hour
Initial position = 60 km/h x 1 hour = 60 km
final position = 120 km/h x 2 hour = 240 km
The average velocity is given by;

Therefore, the average velocity is 180 km/hr