A box is initially at rest on a horizontal, frictionless table. If a force of 10 Newtons acts on the box for 3 seconds

Q1; Short Answer: A box is initially at rest on a horizontal, frictionless table. If a force of 10 Newtons acts on the box for 3 seconds, what is the momentum of the box at the end of the 3 second interval?

ANSWER: 30 NEWTON-SECONDS or 30 KILOGRAM-METER PER SECOND

Q2; Multiple Choice: A block of metal which weighs 60 newtons in air and 40 newtons under water has a density, in kilograms per meter cubed, of:

w) 1000

x) 3000

y) 5000

z) 7000

ANSWER: X -- 3000

Q2; Short Answer: A 10 kilogram body initially moving with a velocity of 10 meters per

second makes a head-on collision with a 15 kilogram body initially at rest. The two objects stick

together. What is the velocity of the combined system just after the collision?

ANSWER: 4 METERS PER SECOND

Q3; Short Answer: A certain spring is known to obey Hooke's Law. If a force of 10

newtons stretches the spring 2 meters, how far will a 30 newton force stretch the spring?

ANSWER: 6 METERS

Q4; Short Answer: A helicopter is ascending vertically with a constant speed of 6 meters

per second relative to the ground. At the instant the helicopter is 60 meters above the ground it

releases a package. What is the magnitude and direction of the velocity of the package, relative to

the ground, the instant the package is released by the helicopter?

ANSWER: 6 METERS/SECOND UP