Inertia is when a object in motion will stay in motion or in a standing still state unless acted upon by a unbalancing force.
Friction is when a object slows down because it is rubbing against another object.
If a object is sliding across a surface, theoretically, it would not stop but because it is on a flat surface it would experience friction, this will disperse some of the kinetic energy that it has thus slowing the object down eventually, after some time, to a stop.
Hope this helps! :)
To solve this, you’d multiply 55 by 4, because he is travelling 55 miles every hour, for four hours, which means 55 miles every hour. The answer would be 220.
M = 40 Kg , g=9.8 m/s² , h = 2 m
PE = m g h
PE = (40) (9.8) (2)
PE = 784 J
KE = PE
½m v² = m g h
½ v² = g h
½ v² = (9.8) (2)
½ v² = 19.6
v² = 19.6×2
v² = 39.2
V = √39.2
V = 6.26 m/s
KE = ½mv²
KE = ½(40) (6.26)²
KE =783.8 J
To calculate the acceleration of the truck, we use the equation of motion
Here, v is final velocity of the truck, u is initial velocity of truck, a is acceleration of the truck and t is time taken.
Given, u = 6 m/s, v = 14 m/s and t = 4 s.
Substituting these values in above equation, we get
.
Thus, the truck acceleration is 
