Question

a car is moving with a velocity of 72 kilometre per hour and it takes 5 seconds to stop after the brakes are applied calculate the force exerted by the brakes on the car is mass along with the passenger is 1500 kg ​

Answer 1

Explanation:

GIVEN:

A CAR IS MOVING WITH A VELOCITY OF 72 KM/H AND IT TAKES 5 SECONDS TO STOP AFTER BRAKES ARE APPLIED.

THEREFORE;

INITIAL VELOCITY =72 KM/H=72×5/18 =20 M/S.

FINAL VELOCITY =0 M/S.

TIME TAKEN= 5 SECONDS

MASS OF CAR=1500 KG.

TO FIND:

FORCE EXERTED BY THE BRAKES.

FORMULAS USED:

☆A=V-U/T.

☆F= M ×A=MA.

WHERE,

A=ACCELERATION

V=FINAL VELOCITY.

U=INITIAL VELOCITY

T=TIME TAKEN.

F=FORCE.

M=MASS.

SOLUTION:

FIRST CALCULATING ACCELERATION BY USING FORMULA:

=A=V-U/T=0-20/5=-20/5= -4 M/S^2.

NOW CALCULATING FORCE USING FORMULA:

F=MA

=1500×(-4)=6000 NEWTON.

HENCE FORCE APPLIED BY THE BRAKES IS 6000 N.

Answer 2

Answer:

6000 newtons

Explanation:

First of all the quantities given in the question is initial velocity, time and mass.

V(Final Velocity) = 0 Since brakes are used.

u(Initial Velocity) = 72kmph when converted into SI units 20 m/s

t (time taken) = 5 seconds

m(Mass) = 1500kg

F = ma

v=u+at

a(acceleration) = v-u/t

a= 0-20/5

= -20/5

= -4 m/s

'a' came in negative because car is deccelerating.

F = ma

= 1500kg x -4m/s

F = -6000 Newtons

F came negative because car breaks are against to the speed of car's motion.