ES 105 1st Midterm

Eight seconds after starting from rest, a freely falling object will have a speed of about (assume we are on earth):

80 m/s

Which mass wasting process has the slowest rate of movement?

creep

what is not true about mudflows?

mudflows do not deposit talus slopes

This operates primarily in areas of permafrost

solifluction

A sack of potatoes weighing 200 N falls from an airplane. As the velocity of fall increases, air resistance also increases. When air resistance equals 200 N, the sack's acceleration in meters per second per second is

0

An object travels 8 m in the first second of travel, 8 m again during the second second of travel, and 8 m again during the third second. Its acceleration in meters per second per second is

0

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 puck sliding at constant velocity is

0 N.

What is the acceleration of a car that maintains a constant velocity of 500km/h for 20s

0 m/s^2

A 6 kg fish swimming at a speed of 1 m/s swallows an absent minded 2-kg fish swimming toward it at 2 m/s. The speed of the larger fish after lunch is

1/4 m/s

A car accelerlates from a rest at 2m/s/s. What is its speed 5s after the car starts moving?

10 m/s

If a freely falling object were somehow equipped with a speedometer, its speed reading would increase each second by about

10 m/s

A 1-kg mass at the earths surface weighs about

10N.

Chuck Norris punches a leaf in midair and brings it from rest up to a speed of 60 m/s in 0.05 s. If the mass of the leaf if 0.01 kg the force of impact on the leaf is about

12 N

An object is pulled eastward with a force of 30N and westward for of 15N. The magnitude of the net force on the object is

15N.

A 5-kg ball has a momentum of 10 kg.m/s. What is the ball's speed?

2 m/s

A girl pulls on a 10-kg wagon with a constant force of 30N. What is the wagons acceleration in meters per second per second?

3.0

If a baseball being thrown goes from zero to 30 m/s in 0.1 s, what is its average acceleration?

300 m/s/s

The force of friction on a sliding object is 30N. The applied force needed to maintain a constant velocity is

30N.

The average momentum of a 50-kg runner who covers 200 m in 30 s is

333 kg.m/s

A car moves 2 times as fast as another identical car. Compared to the slower car, the faster car has

4 times the kinetic enery

A man weighing 800N stands at rest on two bathroom scales so that his weight is distributed evenly over both scales. The reading on each scale is

400 N.

A 400-kg bear grasping a vertical tree slides down at constant velocity. The friction force between the tree and the bear is

4000N.

An empty roller coaster car at an amusement park takes 5 min to make its ride from start to finish. Neglecting friction, a fully loaded car would take

5 min.

A 5kg rock and a 1kg rock are dropped in a vacuum. The force of gravity on the 5kg rock is? (compared with the 1kg)

5 times as much as the force on the 1kg rock

A person is attracted toward the center of the Earth by a 500-N gravitational force. The force of attraction of the Earth toward the person is

500 N

A 10-N falling object encounters 4 N of air resistance. The magnitude of the net force on the object is

6N.

In raising a 18000-N car with a jack, it is noted that for every 0.5 m that the person pushes down on the jack handle, the car rises 0.02m. Ideally, this means the force that the human needs to apply is about

720 N

The scientist to first introduce the concept of inertia was

Galileo

in which case would you have the largest mass of gold? If your chunk of gold weighed 1N on the

Moon

It takes 11 s for a stone to fall to the bottom of a mine shaft. How deep is the shaft?

about 605 m

A lahar is a special type of mass wasting that is restricted to

areas with volcanic deposits

A heavy object and a light object are dropped at the same time from rest in a vacuum. The heavier object reaches the ground

at the same time as the lighter object

Which requires more work: lifting a 50 kg sack vertically 2m or lifting a 25 kg sack vertically 4 m

both require the same amount of work

A freight train rolls along a track with considerable momentum. If it rolls at the same speed but has twice as much mass, its momentum is

doubled

A player catches a ball. Consider the action force to be the impact of the ball against the players glove. The reaction to this force is the

force the glove exerts on the ball

What factors affect mass wasting?

gravity, water, slope angle

When the force that produces an impulse acts for twice as much time as much time, the impulse is

increased by two times

A bowling ball is in equilibrium when it

is at rest, and moves steadily in a straight line path

When a 20 N falling object encounters 5 N of air resistance, its acceleration of fall is

less then g (gravity)

A kilogram is a measure of an objects

mass

A heavy truck and a small truck roll down a hill. Neglecting friction, at the bottom of the hill, the heavy truck will have greater

momentum

A fast moving car hitting a haystack or hitting a cement wall produces vastly different results. Both experience

the same change in momentum and the same impulse

The density of 1 kilogram of iron is

the same on the moon

one object that has twice as much mass as another object also has twice as much

velocity

A force of friction can occur

with sliding objects, in water and in air