To solve this problem we will apply the concepts related to the conservation of momentum. The momentum can be defined as the product between the mass of the object and its velocity, and the conservation of the momentum as the equality between the change of the initial momentum versus the final momentum. Mathematically, this relationship can be described as
Here,
= Mass of each object
= Initial velocity of each object
= Final velocity of each object
According to the statement one of the bodies does not have initial velocity, therefore said term would be zero. And the equation could be rewritten as,
Replacing the values respectively (The mass of your body with its respective speed we would have)
Therefore the initial velocity of the 2kg cart is 0.55m/s
Answer:
See the answers below
Explanation:
This problem can be solved by means of the law of conservation of energy, which tells us that the energy between two points is conserved, that is, remains the same.
That is to say, we have two points, the point A where it starts to move and reaches the point B that is 1.5 [m] high, where it stops.
The key to solving this problem is to identify the types of energies at each point. At point A we have kinetic energy and potential energy where the block moves at speed 3 [m/s] at a height of 4 [m]. Whereas at Point B we only have potential energy, since the body is at a height of 1.5 [m], relative to the ground.
a)
Since between the displacement between points A and B there is a friction force, this friction force decreases the final energy in B, in this way the energy or work of the friction will have a negative sign.
Now replacing in the above equation.
b)
We must use the same equation, but this time eliminating the Working term due to friction.
As we can see without friction the block can reach a higher height
Answer:
60 km/hour.
Explanation:
We'll begin by calculating the total distance traveled by the car. This is illustrated below:
Total distance traveled = sum of distance between PQRST
Total distance = 10 + 5 + 10 + 5
Total distance = 30 km
Next, we shall convert 30 mins to hour. This can obtained as follow:
Recall:
60 mins = 1 hour
Therefore,
30 mins = 30/60 = 0.5 hour.
Finally, we shall determine the average speed of the car as follow:
Distance = 30 km
Time = 0.5 hour
Speed =?
Speed = distance /time
Speed = 30/0.5
Speed = 60 km/hour
Therefore, the speed of the car is 60 km/hour.
The correct statement is
Ultraviolet light has both a higher frequency and a higher radiant energy than visible light.
because ultraviolet light has wavelength smaller than the visible light hence has a greater frequency as compared to visible light. (frequency is inversely related to wavelength. hence smaller the wavelength , greater will be the frequency)
we also know that the radiant energy is directly proportional to the frequency. hence greater the frequency , greater will be the radiant energy.
Since the frequency is greater for ultraviolet light , it radiant energy is also greater