Long Answer question (5 Marks)
3. a) State Newton's Second law of motion
b) Derive the expression for the law.
C) A car of mass 800 kg is travelling with a velocity of 20 m/s. When brakes are applied it stops after
travelling a distance of 8 m. Find retardation and retarding force.
Answers
Answer:
pls use socratic app for these types of questions
Answer:
ans a)Newton's second law states that the acceleration of an object is directly related to the net force and inversely related to its mass. ... So, the force/mass ratio (from the equation acceleration = force/mass) is the same for each. Therefore, the acceleration is the same and they reach the ground at the same time.
b)Derivation of First Equation of Motion
For the derivation, let us consider a body moving in a straight line with uniform acceleration. Then, let the initial velocity be u, acceleration is denoted as a, time period is denoted as t, velocity is denoted as v, and the distance travelled is denoted as s.
c) mass(m)=800kg
initial velocity (u)=20 m/s
final velocity (v) =0 m/s
distance(s)= 8m
We have to find acceleration which is the retardation.
2as = v square - u square
2a×8 = 0 square × 20 square
16a= - 400
a=-400/16
a= -25 m/s
Retarding force:
F=ma
F= 800 × (-25)
F= -20000N