Physical Science Final (Dr. Boelter)(Old Set)
A 5 kg fish swimming at a speed of 1 m/s swallows an absent-minded1 kg fish swimming toward it at 4 m/s. The speed of the larger fish after lunch is __________.
2/3 m/s
A 1 kg chunk of putty moving at 1 m/s strikes and sticks to a 5 kg bowling ball that is initially at rest. After the putty sticks to the ball, both move with a combined momentum of ___________.
0 kgm/s
What is the acceleration of a 50 kg object pushed with a force of 500 N?
10 m/s^2
How much force is needed to accelerate a 66 kg skier at 2 m/s^2?
132 N
A car moves four times as fast as an identical car. Compared to the slow car, the faster car has ___________.
16 times the KE
If you exert 100 J in 50 s, your power output is ____________.
2 W
A karate chop delivers a force of 3000 N to a board that breaks. The force that the board exerts on the hand during this event is __________.
3000 N
A 4-kg ball has a momentum of 12 kgm/s. What is the ball's speed?
4 m/s
The force that propels a rocket is provided by __________.
Its exhaust gases
The average momentum of a 70 kg runner who covers 400 m in 50 s is ____________.
560 kgm/s
A 5 kg block is pulled across a table by a horizontal force of 40 N with a frictional force of 8 N opposing the motion. What is the acceleration of the object?
6.4 m/s^2
A car traveled 60 miles in 1.25 hours. What was its speed in km/hr? (1 mi = 1.6 km)
76.8 km/hr
A 5000 kg freight car runs into a 10,000 freight car at rest. They couple upon collision and move with a speed of 2 m/s. What was the initial speed of the 5000 kg car?
8 m/s
A 2 kg mass is held 4 m above ground. What is the approximate potential energy of the mass with respect to the ground?
80 J
Which of the following has the largest momentum relative to Earth? a. A tightrope walker crossing Niagara Falls b. A pickup truck speeding along a highway c. A Mack truck (semi truck) parked in a parking lot. d. The Science building on UNL's campus
A pick up truck speeding along a highway
If an object moves along a curved path, then it must be____________.
Acted on by a force
A car traveling along the highway needs a certain amount of force exerted on it to stop. More stopping may be required when the car has ____________. a. More mass b. More momentum c. Less stopping distance d. All of the above
All of the above
The amount of air resistance that acts on a wing suit flyer (and a flying squirrel) depends on the flyer's __________.
Area and speed
A constant net force acts on an object. Describe the motion of the object.
Constant acceleration
A ball rolls down a curved ramp. As its speed increases, its rate of gaining speed _____________.
Decreases
As a mass is added to a cart pushed by a constant force, its acceleration _____________.
Decreases
You drop a pillow off the edge of the tallest building on your campus. While the pillow falls, its speed _________.
Increases and acceleration decreases
The acceleration of an object is inversely proportional to _____________.
It's mass
The acceleration due to gravity is lower on the Moon than on Earth. Which of the following is true about mass and weight of an astronaut on the Moon's surface, compared to Earth? a. Mass is less, weight is same. b. Mass is same, weight is less. c. Both mass and weight are less. d. Both mass and weight are the same.
Mass is same, weight is less.
A moving object on which no forces are acting will continue to move with constant __________.
Momentum
When you push an ice cube with a 0.5-N force, the ice cube ____________.
Pushes on you with a 0.5-N force
A heavy rock and a light rock in free fall (zero air resistance) have the same acceleration. The reason the heavy rock doesn't have a greater acceleration is that the __________.
Ratio of force to mass is the same for both
In order to catch a ball, a baseball player extends the hand forward before impact with the ball and lets it ride backward in the direction of the ball's motion upon impact. Doing this reduces the force of impact on the player's hand principally because the ___________.
Relative force is less
Cart A has a mass of 1 kg and is pulled with a force of 1 N. Cart B has a mass of 3 kg and is pulled with a force of 3 N. Which undergoes the greater acceleration?
Same for both
A flowerpot of mass m falls from rest to the ground below, a distance h. Which statement is correct? a. The speed of the pot when it hits the ground is proportional to h. b. The KE of the pot when it hits the ground is proportional to h. c. The KE of the pot when it hits the ground does NOT depend on m. d. The speed of the pot when it hits the ground depends on m.
The KE of the pot when it hits the ground is proportional to h.
It is correct to say that impulse is equal to _________.
The change in momentum
Which of Newton's laws best explains why motorists should buckle up?
The first law
Two parachutists, a heavy person and a light person, jumping from the same altitude have the same size parachute. Who reaches the ground first?
The heavy person
A child's toy is suspended from the ceiling by means of a string. The Earth pulls downward on the toy with its weight force of 8 N. If this is the "action force," what is the "reaction force"?
The toy pulling up on the Earth with an 8 N force
You are standing in a moving bus, facing forward, and you suddenly fall forward. You can imply this from this that the bus's __________.
Velocity decreases
How strongly the planet pulls on you is your _________.
Weight
Choose the correct answer. a. Your weight changes depending on the gravity of the planet your on. b. Your weight never changes despite the planet your on. c. Your mass changes depending on the gravity of the planet your on.
Your weight changes depending on the gravity of the planet your on.
If the speed of a moving object doubles, which of the following also doubles? a. momentum b. kinetic energy c. acceleration d. all of the above
all of the above
The moving object has ___________. a. speed b. energy c. momentum d. all of the above
all of the above
Mass and weight _________.
are two different quantities
Which requires more work: lifting a 50 kg sack vertically 2 m or lifting a 25 kg sack vertically 4 m?
both require the same amount of work
When a car is braked to a stop, its kinetic energy is transformed to ___________.
heat
If you push for an hour against a stationary wall, you do no work is done _____________.
on the wall
A job is done slowly, while an identical job is done quickly. Both jobs require the same amount of work, but different amounts of ____________.
power
When an object is lifted 10 m, it gains a certain amount of potential energy. If the same object is lifted 20 m, its potential energy is ___________.
twice as much
If you push an object twice as far while applying the same force, you do ____________.
twice as much work
