They move in a waves motion
Answer:
C) 40 N/m
Explanation:
If we ASSUME that the spring is un-stretched at the zero cm position
k = F/Δx = 10/0.25 = 40 N/m
Answer:
VR = 
Explanation:
A machine is a device that can be used to overcome a load by the application of an effort through a pivot. Examples are: pulleys, wedge, screw jack, wheel and axle etc.
The wheel and axle is a simple device that can be used to lift a load through a height. Its velocity ratio (VR) can be determined by:
VR = 
Note that for a practical wheel and axle, the radius of the wheel is greater than the radius of the axle.
Answer:
The final velocity of the ball is 39.2 m/s.
Explanation:
Given that,
A ball is dropped from rest from a high window of a tall building.
Time = 4 sec
We need to calculate the final velocity of the ball
Using equation if motion

Where, v = final velocity
u = initial velocity
g = acceleration due to gravity
t = time
Put the value into the formula


Hence, The final velocity of the ball is 39.2 m/s.