Answer:
Explanation:
mass of car, m = 1022 kg
mass of truck, M = 1620 kg
initial velocity of truck, U = 14.5 m/s
initial velocity of car, u = 0 m/s
Let the final velocity of car is v and the final velocity of truck is V.
Collision is elastic, so the coefficient of restitution, e = 1
Use conservation of momentum
initial momentum of car + initial momentum of truck = final momentum of car + final momentum of truck
m x u + M x U = m x v + M x V
0 + 1620 x 14.5 = 1022 v + 1620 V
23490 = 1022 v + 1620 V ..... (1)
Use the formula of coefficient of restitution
1 (14.5 - 0) = v - V
14.5 = v - V
V = v - 14.5 .... (2)
Put in equation (1)
23490 = 1022 v + 1620 (v - 14.5)
23490 = 1022 v + 1620 v - 23490
46980 = 2642 v
v = 17.8 m/s
Put in equation (2)
V = 17.8 - 14.5
V = 3.3 m/s
Thus, the speed of car is 17.8 m/s and the velocity of truck is 3.3 m/s after collision.
Explanation:
Speed of the marathon runner, v = 9.51 mi/hr
Distance covered by the runner, d = 26.220 mile
Let t is the time taken by the marathon runner. We know that the speed of the runner is given by total distance divided by total time taken. Mathematically, it is given by :
t = 2.75 hours
Since, 1 hour = 60 minutes
t = 165 minutes
Since, 1 minute = 60 seconds
t = 9900 seconds
Hence, this is the required solution.
#1
As we know that energy of electromagnetic wave is given by
so here we know that penetrating power will directly depends on its energy and energy inversely depends on wavelength
So here we can say correct answer will be
C) The penetrating power decreases as the wavelength increases.
#2
Speed of sound is maximum in solids and minimum in gas
so here as ice melts into water the speed of sound must have to decrease
so correct answer will be
D) The speed of sound would decrease because sound travels faster through solids than liquids.
#3
mechanical waves required medium to travel while non mechanical waves do not require any medium to travel
so here correct answer will be
A) sound
Answer:
The energies corresponding to each of the allowed orbitals are called energy levels.
Explanation:
A scientist known as Niels Bohr put forward that electrons in an atom covers some permitted orbitals with a specific energy. In other words, the energy of an electron in an atom is not continuous, but 'quantized.' The energies corresponding to each of the allowed orbitals are called energy levels.
To understand this question, you need to understand the concept of acceleration first. Have you ever been in a car and noticed that it was getting faster and faster? That "speeding up" of the car is known as acceleration! Acceleration is essentially the rate at which you speed up.
Okay, so we now know what acceleration is. What are its units? The unit of acceleration is the change in velocity over a period of time:
If you haven't learned about velocity yet, just think about it as speed for now. The funny-looking triangle, ∆, is a symbol for "the change of." For example, if I started walking at 3 then sped up to 5
, then the change in my speed would be 2
, because I started walking 2
faster!
Okay, enough with all the explanations. Hopefully, you understand the units now. Let's take a look at the question. A car accelerates from 4 to 16
in 4 seconds. What would the acceleration be? Let's set up an equation:
a =
a is the acceleration, ∆v is the change in velocity, and t is the time elapsed.
Now, let's plug in our values! ∆v is the change in velocity, and to find that we simply have to subtract 16 by 4
. That makes sense, right? Back to the equation.
a =
a =
(16 - 4 is the change in velocity, and 4 is the number of seconds the car was accelerating)
a =
a = 3 ()
We have our answer! The car's acceleration is 3 meters per second^{2}.
(You might be thinking: Wait. Meters per second squared? The reason for that is because acceleration is the rate at which the speed increases! That makes the unit , which can be simplified down to
)
Let me know if you need clarification on anything I explained here!
- breezyツ