A rocket exerts a horizontal force of 80,000 N for 20 s on a 3000-kg rocket sled

Question

A rocket exerts a horizontal force of 80,000 N for 20 s on a 3000-kg rocket sled that is initially at rest. The coefficient of friction between the sled and the ground (which is level) is 0.2 (Ignore air resistance.) What is the magnitude of the friction force on the sled? 5880 N ou are correct. Previous Tries r receipt no. is 155-8946 What is the magnitude of the acceleration of the sled while the rocket is firing? 24.7 m/s 2 ou are correct. r receipt no. is 155-9521 Previous Tries What is the speed of the sled when the rocket stops firing? Submit Answer Incorrect. Tries 3/99 Previous Tries What is the distance that the rocket travels while the rocket is firing? 4940 m You are correct Your receipt no. is 155-2148 Previous Tries What is the magnitude of the acceleration of the sled after the rocket stops firing? Submit Answer Tries 0/99 How far from its starting point does the rocket sled come to rest again? ( Submit AnswerTries o/99 How much time elapses between the moment when the rocket starts firing and the moment when the sled comes to rest again? Q Submit Answer Tries 0/99

Explanation / Answer

here,

force , F =80 000 N

mass , m= 3000 kg

uk = 0.2

time , t1 = 20 s

the magnitude of frictional force , ff = uk * m * g

ff = 0.2 * 3000 * 9.81 N

ff = 5886 N

the magnitude of accelration is 24.7 m/s^2

let the final speed of sled be v

v = u + a * t1

v = 0 + 24.7 * 20 = 494 m/s

s1 = 4940 m

the accelration of sled after the rocket stops firing , a' = - ff/m

a' = - 1.96 m/s^2

the magnitude of accelration of sled after the rocket stops firing is 1.96 m/s^2

let the stopping distance be s2 from where the rocket stops firing

v^2 - u^2 = 2 * a' * s2

494^2 = 2 * 1.96 * s2

s2 = 62254 m

the distance travelled from the starting point is ( s1 +s2 = 67194 m)

let the time taken to stop be t2 after the rocket stops firing

v = u + a' * t2

t2 = 494 /1.96 = 252 s

the time taken between the moment when the rocket starts firing and the moment when the sled comes to rest ( t1 + t2 = 272 s)

Related Questions

Navigate

• Browse (All)
• Browse A
• Subjects

---

---

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.