Question

car moves at a speed of 72km/h it is stopped by applying brakes which produces a uniform acceleration of -a.6m/s2 how much distance will the vehicle move before coming to stop​

Answer 1

Given

A car moves at a speed of 72km/h it is stopped by applying brakes which produces a uniform acceleration of -6m/s2

To find

how much distance will the vehicle move before coming to stop

Solution

• Initial velocity (u) = 72km/h
• Final velocity (v) = 0
• Acceleration (a) = -6m/s²
• Distance (s) = ?

→ u = 72km/h

→ u = 5/18 × 72

→ u = 20m/s

*According to third equation of motion*

→ v² - u² = 2as

→ (0)² - (20)² = 2*(-6)*s

→ 0 - 400 = -12s

→ -400 = -12s

→ s = 400/12 = 33.3m

Hence, distance travelled by a car is 33.3m

Note

(★) v = u + at {first equation of motion}

(★) s = ut + ½ at² {second equation of motion}