Explanation:
It is given that,
Mass of the block, m = 3 kg
Initially, the block is at rest, u = 0
Force acting on the block, P = 12 N
The coefficient of kinetic friction between the block and the surface is, 
We need to find the rate is the force P doing work on the block at t = 2.0 s. The rate at which work is done is called the power. Let is equal to P'
Frictional force acting on the block, 
So, the net force acting on the block, F = P - f
Let a is the acceleration of the block, 
Let v is the velocity of the block after 2 seconds. So,
v = 4.08 m/s
Power, 
So, the force P is doing work on the block at the rate of 48.96 watts.
Answer:
Before: 0 m/s
After: -4 m/s
Explanation:
Before: Since you and your beau started at rest, your beau initial velocity is 0 m/s.
After: Since we have to conserve momentum,
momentum before push = momentum after push.
The momentum before push = 0 (since you and your beau are at rest)
momentum after push = m₁v₁ + m₂v₂ were m₁ = your mass = 60 kg, v₁ = your velocity after push = 3 m/s, m₂ = beau's mass = 45 kg and v₂ = beau's velocity.
So, m₁v₁ + m₂v₂ = 0
m₁v₁ = -m₂v₂
v₂ = -m₁v₁/m₂ = -60 kg × 3 m/s ÷ 45 kg = -4 m/s
So beau moves with a velocity of 4 m/s in the opposite direction
The average speed <em>appears to be</em> (distance) / (time) =
(length of the cable) / (time from when a pulse goes in until it comes out the other end) .
That's 1,200,000 meters/ 0.006 second = 2 x 10^8 = <em>2 hundred million m/sec</em>
That figure is about 66.7% of the speed of light in vacuum.
The reason I went through all of this detail was to point out that this is
NOT necessarily the speed of light in this glass, for two reasons.
1). The path of light through an optical fiber is not straight down the middle. In the original fibers of 20 or 30 years ago, the light bounced back and forth off the inside walls of the fiber, and zig-zagged its way along the length. In current modern fibers, it still zig-zags, but it's a more gentle, up-and-down curved path. In either case, the distance covered by the light inside the fiber is more than the straight length of the cable, and the time it takes it to come out the other end is more than its actual speed inside the glass would have meant if it could have traveled straight through the pipe.
2). This problem talks about an optical fiber that's 1,200km long. There is loss in optical fiber, and you're NOT going to get light all the way through a single piece of it that's something like 745 miles long. It takes electronic repeaters, "boosters", and regenerators every few miles to keep it going, and these devices add "latency" or time delay in the process of going through them. That delay in the electronics shows up as apparent delay through the fiber-optic cable, and it makes the speed through the glass appear to be slower than it actually is.
Answer:
The final velocity of the object is 330 m/s.
Explanation:
To solve this problem, we first must find the acceleration of the object. We can do this using Newton's Second Law, given by the following equation:
F = ma
If we plug in the values that we are given in the problem, we get:
42 = 7 (a)
To solve for a, we simply divide both sides of the equation by 7.
42/7 = 7a/7
a = 6 m/s^2
Next, we should write out all of the information we have and what we are looking for.
a = 6 m/s^2
v1 = 0 m/s
t = 55 s
v2 = ?
We can use a kinematic equation to solve this problem. We should use:
v2 = v1 + at
If we plug in the values listed above, we should get:
v2 = 0 + (6)(55)
Next, we should solve the problem by performing the multiplication on the right side of the equation.
v2 = 330 m/s
Therefore, the final velocity reached by the object is 330 m/s.
Hope this helps!
The correct answer is A.
Quantum physics is the branch of science which deals with the behavior of matter and light on atomic and subatomic level. So, to understand the motion of an atom we would need quantum physics. Motion of a ball and a galaxy can be understood by Newtonian mechanics.
