Answer:
6.21 m/s
Explanation:
Using work energy equation then

where d is displacement from initial to final position, v is velocity and subscripts a and b are position A and B respectively, m is mass of collar, g is acceleration due to gravity
Substituting 1 Kg for m, 0.4m for h,
as 0, 9.81 for g then

Newton's first law of motion states that an object that is resting (not moving) will stay motionless unless an external force acts on it and an object in motion will stay in motion unless an outside force acts on it. This law is known as newton's law of inertia.
Answer:
Explanation:
Force - frictional Force = m * a
20N - 5N = 5 * a
15N = 5*a
15N / 5 = a
a = 3 m/s^2
You should note a couple of things.
1. The frictional Force always opposes the direction of motion. In this case it is minus and the 20 N is plus. It makes the acceleration less. If the friction force was not there then 20 N = m * a
20N = 5 kg * a
a = 20/5
a = 4 m/s^2.
Answer:
Work = 165670.4 J = 165.67 KJ
Explanation:
First, we will find the deceleration of the car, using the 3rd equation of motion:

where,
a = deceleration = ?
s = skid distance = 40 m
vf = final speed = 0 m/s
vi = initial speed = 17.2 m/s
Therefore,

the negative sign indicates deceleration here.
Now, we will calculate the braking force applied by the brakes on the car:

the negative sign indicates braking force.
Now, we will calculate the work done using the magnitude of this force:

<u>Work = 165670.4 J = 165.67 KJ</u>