Well for starters, gravity keeps things down on Earth. Also, gravity applies its force on to cars to maintain stability by forcing the tires to make constant contact to the ground creating friction between the rubber and road surface allowing the car to be moved. I'm sure someone else has better ideas!
Answer:
v=0.94 m/s
Explanation:
Given that
M= 5.67 kg
k= 150 N/m
m=1 kg
μ = 0.45
The maximum acceleration of upper block can be μ g.
a= μ g ( g = 10 m/s²)
The maximum acceleration of system will ω²X.
ω = natural frequency
X=maximum displacement
For top stop slipping
μ g =ω²X
We know for spring mass system natural frequency given as

By putting the values

ω = 4.47 rad/s
μ g =ω²X
By putting the values
0.45 x 10 = 4.47² X
X = 0.2 m
From energy conservation


150 x 0.2²=6.67 v²
v=0.94 m/s
This is the maximum speed of system.
Answer:
C is the right answer.
Body massager uses electrical energy to move back and forth. In this sense, a motor is being used for the operation