Question

a car strating from stationary condition to obtain the speed of 81km/hour in 4.5 second if the produced engine force is 5000 N find the mass of that car​

Answer 1

Given data:-

{ Initial velocity = u; Final velocity = v; Time = t; Force = F; Acceleration = a; Mass = m }

—› u = 0

—› v = 81 km/hour

—› t = 4.5 sec

—› F = 5000 N

Solution:-

—› v = 81 km/hour

—› v = [{81×1000}/{60×60}] m/sec

—› v = [81000/3600] m/sec

—› v = [810/36] m/sec

—› v = 22.5 m/sec

Now,

—› a = { v - u }/t

—› a = { 22.5 - 0 }/4.5

—› a = 22.5/4.5

—› a = 5 m/s²

Now,

—› F = m × a

—› 5000 = m × 5 i.e.

—› m = 5000/5

—› m = 1000 kg

Hence the mass of car is 1000 kg.

Answer 2

Answer:

initial velocity (u) = 0

final velocity(v ) = 81 km/h = 22.5 m/s.

time(t)= 4.5 sec

force (f ) =5000 N

so mass(m) = force/ accelaration

Explanation:

accelaration = initial velocity -final velocity divided by time .

a = v-u/t

= 22.5 - 0/ 4.5 =5 m/s

M = F/A

= 5000/5 = 1000 kg.