a spaceship traveling in space at 300km/s fires it's engine for 15 seconds such that it's final velocity is 600km/s find The
a. acceleration
b. distance travelled in one minute from the time of firing
Answers
Answer:
- Acceleration of Spaceship = 20,000 m/s²
- Distance travelled by Spaceship in one minute from the time of firing = 33,750 km
Explanation:
Given that,
- Initial velocity of spaceship, u = 300 km/s = (300 × 1000) m/s = 300,000 m/s
- Final velocity of spaceship, v = 600 km/h = (600 × 1000) m/s = 600,000 m/s
- Time taken for velocity change, t = 15 sec
We need to find, acceleration of spaceship, a =?
Using First equation of motion
→ v = u + a t
→ 600,000 = 300,000 + a × 15
→ a = ( 600,000 - 300,000 ) / 15
→ a = 300,000 / 15
→ a = 20,000 m/s²
Hence,
Acceleration of spaceship is 20,000 m/s².
Now,
We need to calculate the distance covered by Spaceship in one minute from firing, s =?
Let, distance covered by spaceship in the 15 seconds of accelerating be s₁
so, Using second equation of motion
→ s₁ = 300,000 × 15 + 1/2 × 20,000 × 15²
→ s₁ = 4,500,000 + 2,250,000
→ s₁ = 6,750,000 m = 6,750 km
Now, for next (60-15) seconds means 45 seconds Spaceship will travel with uniform speed of 600,000 m/s, hence acceleration will be zero
Hence, distance covered by Spaceship in these 45 seconds be s₂
→ distance = speed × time
→ s₂ = 600,000 × 45
→ s₂ = 27,000,000 m = 27,000 km
Therefore,
→ total distance covered by spaceship in 1 min = s = s₁ + s₂ = 6,750 km + 27,000 km = 33,750 km.