Wave speed = frequency * wavelength
Wave speed = 4 * 25
Wave speed = 100 m/s
Answer: 25.38 m/s
Explanation:
We have a straight line where the car travels a total distance
, which is divided into two segments
:
(1)
Where 
On the other hand, we know speed is defined as:
(2)
Where
is the time, which can be isolated from (2):
(3)
Now, for the first segment
the car has a speed
, using equation (3):
(4)
(5)
(6) This is the time it takes to travel the first segment
For the second segment
the car has a speed
, hence:
(7)
(8)
(9) This is the time it takes to travel the secons segment
Having these values we can calculate the car's average speed
:
(10)
(11)
Finally:
Answer:
The magnitude of Force is 8.58×10⁵N and direction is upwards
Explanation:
The work beam does on the pile driver is given by
W=(FCos180°)Δx= -F(0.088m)
From work energy theorem

Choosing y=0 at the the level where the driver first contacts the beam and vi=0 at yi=+3.40m and comes to rest again vf=0 at yf= -0.088m
So

The magnitude of Force is 8.58×10⁵N and direction is upwards