Newton's 1st Law and Linear Motion
A hockey puck slides along an icy pond. Without any kind of friction, how much force is needed to sustain sliding?
none
A 200 N sack of onions falls from an airplane. When the air resistance of the fall equals 200 N, the acceleration of the sack is
0 m/s2
Work is done in lifting a barbell. How much work is done in lifting a barbell that is twice as heavy the same distance?
Twice as much
If a red-hot thumbtack is immersed in room temperature water, the direction of heat flow will be from the
red-hot thumbtack to the water
A 1-meter-long pendulum has a bob with a mass of 1 kg. Suppose that the bob is now tied to a different string so that the length of the pendulum is now 2 m. How will the period of the pendulum change?
it will increase
What is the net force on a box of chocolates when pushed across a table with a horizontal force of 10 N while friction between it and the surface is 6 N.
4N
Toss a ball vertically upward and its acceleration at the top of its path is
10 m/s2
A job can be done slowly or quickly. Both may require the same amount of work, but different amounts of
Power
You heat a half-cup of tea and its temperature rises by 4 degrees celsius. How much will the temperature rise if you add the same amount of heat to a full cup of tea?
2 degrees Celsius
If the frequency of a particular wave is 20 Hz, its period is
1/20 second
A mosquito flying at 2 m/s encounters a 2 m/s breeze blowing in the opposite direction, giving it a resulting speed over the ground of...
0 m/s
You drop a pillow off the edge of the tallest building in your city. While the pillow falls, its speed _____________ while its acceleration _______________.
increases
decreases
If fast Freda doubles her running speed, she also doubles her
momentum
When a sample of 0 degree Celsius water is heated, it first
contracts
A wave with wavelength 10 meters and time between crests of 0.5 second is traveling in water. What is the wave speed?
20 m/s
The Earth moves about 30 km/s relative to the sun. But when you jump upward in front of a wall, the wall doesn’t slam into you at 30 km/s. A good explanation for why it doesn’t is that
both you and the wall are moving at the same speed before, during and after your jump
A huge GMC truck and a Honda Civic traveling at the same speed collide head-on. The collision force is greatest on the
The force of gravity between two planets depends on two things, what are they?
masses and distance apart
If you hold one end of a metal bar against a piece of ice, the end in your hand will soon become cold. Does cold flow from the ice to your hand?
No
Interference is a property of
both sound and light
Jake walks east through a passenger car on a train that moves 10 m/s in the same direction. Jake’s speed relative to the car is 2 m/s. Jake’s speed relative to an observer at rest outside the train is
12 m/s
When a cannon is fired, the acceleration of the cannon and the cannonball are different because the
masses are different
If the masses of two planets are each somehow doubled, the force of gravity between them
quadruples
Although warm air rises, why are mountaintops cold and snow covered, while the valleys below are relatively warm and green?
Warm air cools when rising or
there is a thick insulating blanket of air above valleys
The blueness of the daytime sky is due mostly to light
scattering