Day 3

Question 1

A projectile is fired with a horizontal velocity of 30 m/s from the top of a cliff 80 m high. How far from the foot of the cliff will it strike?

a. 112m
b. 230 m
c. 121 m
d. 151m

Answer 1

c. 121 m

Question 2

A 5.00 kg object is to be given an upward acceleration of 0.30 m/s2 by a rope pulling straight upward on it. What must be the tension in the rope?
a. 65.4 N b. 45.2 N c. 50.5 N d. 38.7 N

Answer 2

c. 50.5

Question 3

3. An object is dropped from rest from a height of 49 meters. What is the speed of the object as it hits the ground?
   a. 35 m/s b. 31 m/s c. 28 m/s d. 19 m/s

Answer 3

b. 31 m/s

Question 4

4. An 8-gram bullet is fired horizontally into a 9-kg block of wood and sticks in it. The block, which is free to move, has velocity of 40 cm/s after impact. Find the initial velocity of the bullet.
   a. 450 m/s b. 350 m/s c. 220 m/s d. 510 m/s

Answer 4

a. 450 m/s

Question 5

5. An object travelling a circular path makes 1200 revolutions in 1 hour. If the radius of the path is 10 m, calculate the speed of the object.
   a. 19 m/s b. 21 m/s c. 20 m/s d. 22 m/s

Answer 5

b. 21 m/s

Question 6

6. A stone is thrown straight upward and it rises to a height of 20 m. with hat speed was it thrown?
   a. 12.6 m/s b. 19.8 m/s c. 17.7 m/s d. 23.8 m/s

Answer 6

b. 19.8 m/s

Question 7

7. A train is travelling with a speed of 60 mi/hr is brought to an emergency stop in 2000 f. what is the time required for the train to stop?
   a. 50 s b. 35 s c. 46 s d. 60 s

Answer 7

c. 46 s

Question 8

8. A 0.25 hp motor is used to lift a load at the rate of 5.00 cm/s. how great a load can lift at this constant speed?
   a. 381 kg b. 350 kg c. 421 kg d. 400 kg

Answer 8

a. 381 kg

Question 9

9. By the use of the pulley, a man raises a load 120 lb to a height of 40 ft in 65 seconds. Find the average horsepower required.
   a. 0.18 hp b. 0.19 hp c. 0.13 hp d. 0.04 hp

Answer 9

c. 0.13

Question 10

10. A certain cable is suspended between two supports at the same elevation and 50 m apart. The load is 50 N/m horizontal length including the weight of the cable. If the sag of the cable is 3m, calculate the total length of the cable.
    a. 40.12 m b. 25.40 m c. 50.48 m d. 60.24 m

Answer 10

c. 50.48 m