Answer:
The wavelength of the waves created in the swimming pool is 0.4 m
Explanation:
Given;
frequency of the wave, f = 2 Hz
velocity of the wave, v = 0.8 m/s
The wavelength of the wave is given by;
λ = v / f
where;
λ is the wavelength
f is the frequency
v is the wavelength
λ = 0.8 / 2
λ = 0.4 m
Therefore, the wavelength of the waves created in the swimming pool is 0.4 m
Circumference of the tire = (2 pi) x (radius)
= (2 pi) x (0.62 meter)
= 3.9 meters
If the tire never slips or skids, then the speed of the vehicle is
speed = (distance) / (time to cover the distance)
= (5 x 3.9 meters) / 1 second
= 19.48 meters/second .
(about 43.6 miles per hour) .
We can't say anything about the vehicle's velocity, because we have
no information about the direction in which it's heading.
Explanation:
We know that a changing magnetic field induces a current in a conductor. For that reason a generator basically consist an element that produces a magnetic field that changes over time and a conductor where the current will be induced.
This element that produces a magnetic field can be one of the following:
- A permanent magnet: Which is basically like a regular magnet. The magnetic field that a permanent magnet produces does not change over time, we need a motor or any other external force to move the axis of the generator and cause the magnetic field to change.
- An electro-magnet. Which is basically a DC current flowing through a conductor. Basically, when current flows through a conductor it behaves exactly like a magnet. So what we commonly do, is to connect a conductor to a DC battery, and it will create a magnetic field.
Like we are using a DC battery to create a magnetic field, then the magnetic field won't change over time either. So we still need an external force to move the axis of the generator to produce AC electricity.
28J because mechanical energy is the sum of the potential energy and kinetic energy
Answer:
111.5 m
Explanation:
Given that You are driving to the grocery store at 14 m/s. You are 115 m from an intersection when the traffic light turns red. Assume that your reaction time is 0.50 s and that your car brakes with constant acceleration.
Use first equation of motion
V = U - at
Since the car is going to rest, V = 0 and a = negative
0 = 14 - a × 0.5
0.5a = 14
a = 14 /0.5
a = 28 m/s^2
Let us use second equation of motion
S = Ut - 1/2at^2
S = 14 × 0.5 - 0.5 × 28 × 0.5^2
S = 7 - 3.5
S = 3.5 m
115 - 3.5 = 111.5
Therefore, you are 111.5 metres from the intersection (in m) when you begin to apply the brakes.
