Question

A car moving with a velocity of 10 ms and with a uniform acceleration gains a velocity of 30 ms after travelling a distance of 4 km. The time taken is ​

Answer 1

☀️ Given that: A car moving with a velocity of 10 m/s and with a uniform acceleration gains a velocity of 30 m/s after travelling a distance of 4 km

     Need to find: The time taken

Must Know that:

• According to second equation of motion v² = u² + 2as

• According to first equation of motion v = u + at

Where,

v is final velocity ( 30m/s )

u is initial velocity ( 10m/s )

a is acceleration

s is distance travelled ( 4km = 4000m )

t is time taken

Solution:

• Finding acceleration-

→ v² = u² + 2as

→ 30² = 10² + 2 × a × 4000

→ 900 = 100 + 8000a

→ 900 - 100 = 8000a

→ 800 = 8000a

→ a = 800/8000

→ a = 1/10

→ a = 0.1 m/s²

• Finding time taken-

→ v = u + at

→ 30 = 10 + 1/10 × t

→ 30 - 10 = t/10

→ 20 = t/10

→ t = 20 × 10

→ t = 200s

⠀━━━━━━━━━━━━━━━━━━━  

• Henceforth, the time taken by the car to travel the distance is 200s

Answer 2

Answer:

solution:-

1. v square equals to u square +2as
2. 30 square= 10 square +2×a ×400
3. 900=100+ 8000a
4. 900-100=8000a
5. 800-8000a
6. a=800/8000a
7. a=800/8000a
8. a=1/10

Explanation:

1. v=u+at
2. 30=10+1/10×t
3. 30-10=t/10
4. 20=t/10
5. t=20×10
6. t=200s