Week 9: Elastic Properties and Impulse 1. Consider a 7000 kg orbiter traveling t

Question

Week 9: Elastic Properties and Impulse 1. Consider a 7000 kg orbiter traveling through space near Mars with a built-in motor. If the motor provides a 650 N force, how long must the motor run in order for the velocity of the craft to change from 100 km/h to 113 km/h? The orbiter is not well made. It loses some of its shielding in the journey, in total, 400 kg. At the same time, the orbiter's speed must be increased from 113 km/h to 120 km/h. What force is required of the motor if it is to get to speed in 2 hours? a. b. Engineers are testing a new material from which a spring has been made. A weight has been added to the spring and one engineer records that the spring has stretched by 4 cm. The weight is removed and another weight is added. Another engineer records that this time, the spring stretched only 2 cm. The engineer deduces that the weight used had a mass of 0.6 kg. 2. a. What is the spring constant of the material? b. What was the mass of the original weight? c. How much would the spring stretch if a 3 kg weight was used?

Explanation / Answer

1.)

Impulse = change in momentum

F*t = d(m*v)

a) 100 km/hr = 27.778 m/s; 113 km/hr = 31.388 m/s

F*t = m*(v2 - v1)

650*t = 7000* (31.388- 27.778)

t=38.876 seconds

b) 120 km/hr = 33.333 m/s

F*t= (m2v2 - m1v1)

F* 2*3600 = 6600*33.333 - 7000*31.388

F=0.03638 N

2.)

a)Using

mg=kx

0.6*9.8=k*0.02

k= 294 N/m

b) Again, mg= kx

m*9.8 = 294*0.4

m= 1.2 kg

c) Mg = kx

3*9.8 = 294*x

x=0.1 m = 10 cm

Related Questions

Navigate

• Browse (All)
• Browse W
• Subjects

---

---

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