EP 201 Exam 1

When a karate chop breaks a board with a 3000 N blow, the amount of force that acts on the hand is A) 3000 N B) 6000 N C) zero D) 1500 N

A) 3000 N

A skydiver's terminal velocity will be greatest if she falls A) head first B) lying flat on her stomach C) lying flat on her back D) with her parachute open

A) head first

Which concept is being illustrated when a tablecloth is quickly yanked beneath dishes resting on a table? A) inertia B) support force C) equilibrium D) friction

A) inertia

Padded dashboards in cars are safer in an accident than non-padded ones because passengers hitting the dashboard encounter A) lengthened time of impact B) shorter time of contact C) increased momentum D) decreased impulse

A) lengthened time of impact

Something something a distance of 8 meters in the first second of travel, another 8 meters during the next second, and 8 meters again during the third second. Its acceleration is A) 5 m/s^2 B) 0 m/s^2 C) 8 m/s^2 D) 24 m/s^2

B) 0 m/s^2

When a ball thrown straight upwards reaches the very top of its path, its acceleration is A) 5 m/s^2 B) 10 m/s^2 C) zero D) none of the above

B) 10 m/s^2

If you double the net force on an object, you'll double its A) velocity B) acceleration C) speed D) all of the above

B) acceleration

A moving van with a stone lightly glued to the midpoint of its ceiling smoothly moves at constant velocity. When the glue gives way, the stone falls and hits the floor A) behind the midpoint of the ceiling B) exactly below the midpoint of the ceiling C) ahead of the midpoint of the ceiling D) none of the above

B) exactly below the midpoint of the ceiling

An automobile and a golf cart traveling at the same speed collide head-on. The impact force is A) greater on the automobile B) the same for both C) greater on the gold cart

B) the same for both

To catch a fast-moving ball, you extend your hand forward before contact with the ball and let it ride backwards in the direction of the ball's motion. Doing this reduces the force of contact on your hand principally because the A) relative velocity is less B) time of contact is increased C) time of contact is decreased D) force of contact is reduced E) none of the above

B) time of contact is increased

Nellie pulls on a 10-kg wagon with constant horizontal force of 30 N. If there are no other horizontal forces, what is the wagon's acceleration? A) 300 m/s^2 B) 0.3 m/s^2 C) 3.0 m/s^2 D) 30 m/s^2 E) 10 m/s^2

C) 3.0 m/s^2

A pot that falls from a ledge and hits the ground 45 m below hits the ground at A) more than 120 m/s B) 120 m/s C) 30 m/s D) 60 m/s

C) 30 m/s

You're driving down the highway and a bug splatters into your windshield. Which undergoes the greater change in momentum during the time of contact? A) the bug B) your car C) both the same

C) both the same

The normal force that acts on a block of ice that slides up a ramp A) becomes greatest when the ramp is vertical B) is equal to mg at all angles C) decreases as the slope of the ramp increases

C) decreases as the slope of the ramp increases

Phil Physiker standing at the edge of a cliff throws one ball straight up and another ball straight down, both with the same speed. Neglecting air resistance, which ball hits the ground below with the greater speed? A) the one thrown downward B) the one thrown upward C) neither, both hit with the same speed

C) neither, both hit with the same speed

Two identical gliders slide towards each other on an air track. One moves at 1 m/s and the other at 2 m/s. They collide, stick, and moves at A) 1.5 m/s B) 1/3 m/s C) 3/4 m/s D) 1/2 m/s E) 1/6 m/s

D) 1/2 m/s

A bird flying at 8 km/h in a 6 km/h crosswind has a resultant speed of A) 6 km/h B) 14 km/h C) 8 km/h D) 10 km/h

D) 10 km/h

A 10 N falling object encounters 4 N of air resistance. The net force on the object is A) 10 N B) 0 N C) 4 N D) 6 N E) none of the above

D) 6 N

A package falls off a truck that is moving at 30 m/s. Neglecting air resistance, the horizontal speed of the package just before it hits the ground is A) zero B) more than 30 m/s C) less than 30 m/s but more than zero D) about 30 m/s

D) about 30 m/s

A hockey puck is set in motion across a frozen pond. If ice friction and air resistance are neglected, the force required to keep the the puck sliding at constant velocity is A) equal to its weight B) equal to its mass times its weight C) equal to its weight divided by its mass D) none of the above

D) none of the above

The distance a freely falling object falls from rest in one-half second is A) 6 m B) 4 m C) 2 m D) none of the above

D) none of the above

A light woman and a heavy man jump from an airplane at the same time and open their same-size parachutes at the same time. Which person will get to the ground first? A) both should arrive at the same time B) the light woman C) not enough information D) the heavy man

D) the heavy man