Wave speed = frequency * wavelength
Wave speed = 4 * 25
Wave speed = 100 m/s
Answer:
acceleration 8 km/h/s south
Explanation:
First of all, let's remind that a vector quantity is a quantity which has both a magnitude and a direction.
Based on this definition, we can already rule out the following two choices:
distance: 40 km
speed: 40 km/h
Since they only have magnitude, they are not vectors.
Then, the following option:
velocity: 5 km/h north
is wrong, because the car is moving south, not north.
So, the correct choice is
acceleration 8 km/h/s south
In fact, the acceleration can be calculated as

where
v = 40 km/h is the final velocity
u = 0 is the initial velocity
t = 5 s is the time
Substituting,

And since the sign is positive, the direction is the same as the velocity (south).
Answer:
5.71428571422 m/s
Explanation:
u = Initial velocity = 20 m/s
v = Final velocity
s = Displacement
a = Acceleration
Time taken = 15-1 = 14 s
Distance traveled in 1 second = 


The speed as she reaches the light at the instant it turns green is 5.71428571422 m/s
Answer:
Speed = 10 km/hr
Explanation:
Speed = Distance / Time
Since we have to convert it into minutes to hours ( because it is km/hr )
45 minutes = 0.75 hours
Therefore,
Speed = 7.5 / 0.75
= <u>10 km/hr </u>
<u></u>
<u>Hope it helps!</u>
Answer:
<em>v = 381 m/s</em>
Explanation:
<u>Linear Speed</u>
The linear speed of the bullet is calculated by the formula:

Where:
x = Distance traveled
t = Time needed to travel x
We are given the distance the bullet travels x=61 cm = 0.61 m. We need to determine the time the bullet took to make the holes between the two disks.
The formula for the angular speed of a rotating object is:

Where θ is the angular displacement and t is the time. Solving for t:

The angular displacement is θ=14°. Converting to radians:

The angular speed is w=1436 rev/min. Converting to rad/s:

Thus the time is:

t = 0.0016 s
Thus the speed of the bullet is:

v = 381 m/s