Question

A truck of mass 5000 kg moving with a velocity of mass 90 km/h hits a wall

and comes to rest in 25 second find the force exerted by the car on the wall.​???​

Answer 1

Answer:

F =m ×a

m=1000kg

initial velocity = 36km/h

36km \: per \: hour = 36 \times \frac{5}{18} = 10 \: metr \: persecond36kmperhour=36×

18

5

=10metrpersecond

final velocity = 0

time = 5 seconds

a = \frac{v - u}{t} = \frac{0 - 10}{5} = - 2a=

t

v−u

=

5

0−10

=−2

F = ma

\begin{gathered} = 1000 \times ( - 2) = \\ = - 2000 \: newton\end{gathered}

=1000×(−2)=

=−2000newton

Answer 2

Given :-

• A truck if mass 5000 kg moving with a velocity of mass 90 km/h hits a wall and comes to rest in 25 second

To find :-

• The force exerted by the car on the wall

Solution :-

• Mass of truck (m) = 5000kg
• Initial velocity (u) = 90km/h
• Find velocity (v) = 0
• Time taken (t) = 25 sec

→ Initial velocity = 90km/h

→ u = 90 × 5/18

→ u = 25m/s

According to first equation of motion

→ v = u + at

→ 0 = 25 + a × 25

→ 25a = - 25

→ a = - 1 m/s²

Now,

• As we know that

→ Force = mass × acceleration

→ F = m × a

→ F = 5000 × (-1)

→ F = - 5000N

Hence,

• The force exerted by the car on the wall is - 5000N
• Minus shows force exerted in opposite direction