Which of the following has three significant figures? 1.00081 kg 8.060 times 10^

Question

Which of the following has three significant figures? 1.00081 kg 8.060 times 10^11 m 305.00 cm 305.0cm 0.0500 mm The average density of blood is 1, 06 times 10^3 kg/m^3. If you donate a pint of blood to the Red Cross, what mass of blood have you donated, in grams? (1 pt = 1/2 L, 1 L = 1000 cm^3). 5.30 g 0.530 g 5.30 times 10^3 g 5.30 times 10^5 g 530 g If you run a complete loop around an outdoor track (400 m) in 100 s, your average speed is 0.25 m/s Zero 40,000 m/s 4 m/s 8 m/s A motorist travels for 3.0 h at 80 km/h and 4.0 h at 60 km/h. What is her average speed for the trip? 74 km/h 140 km/h 70 km/h 69 km/h 73 km/h A jet fighter plane is launched from a catapult on an aircraft carrier. It reaches a speed of 24 m/s at the end of the catapult, and this requires 2 s. Assuming the acceleration is constant, what is the length of the catapult? 16 m 66 m 24 m 42 m 84 m A bullet shot straight up returns to its starting in 10 s. Its initial speed was 98 m/s 45 m/s 9.8 m/s 24.5 m/s 49 m/s

Explanation / Answer

1. B

Option B has three significant figures that is 8.060*10^11 m

remaining all are of A -5 significant figures

       C - of 0 significant figures

           D - 0 significant figures

           E -4 significant figures.
2. E
density of blood is d = 1.06*10^3 kg /m3

donated blood of volume is 0.5L = 0.5*1000*10^-6 m^3

now density d = m/v ==> m = d*v = 1.06*10^3 *0.5*1000*10^-6 = 0.53 kg = 530 g

answer is option E---------------->>> Answer

3. D

   average speed is v = distance / time = 400 /100 = 4 m/s ------------>>D

4. C
   v1 = 80 kmph = 80*5/18 m/s = 22.22 m/s , t1 = 3 h = 3*3600 = 10800 s

   V2 = 60 kmph = 60*5/18 m/s = 16.67 m/s , t2 = 4 h = 4*3600 = 14400 s
  

average speed of the trip is V1+V2/2 = 80+60/2 = 70 kmph

5.c

   v= 24 m/s

   t = 2 s
using equations of motion

v = u+at

a = v/t = 24/2 = 12 m/s2
and

s = 0+ 0.5*12*2^2 m = 24 m

length of the catapult is s = 24 m

6. E

   time of flight T = 2u/g ==> u = T*g/2 = 10*9.8/2 = 49 m/s -------------->> Answer

Related Questions

Navigate

• Browse (All)
• Browse W
• Subjects

---

---

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