Physics

An object released from rest on another planet requires one second to fall a distance of 6 meters. What is the acceleration in meters per second per second due to gravity on this planet?

12

A car traveling at 22 m/s comes to an abrupt halt in 0.1 second when it hits a tree. What is the deceleration in meters per second per second of the car?

220

A ball thrown straight upward takes 10 seconds to go up and return to the ground. Because of air resistance, the time taken for the ball just to go up is

Less than 5.

A ball is thrown upwards. Neglecting air resistance, what initial upward speed does the ball need to remain in the air for a total time of 10 seconds?

about 50 m/s - (Vf = Vi + a*t; a=g=10m/s; 0=Vi+10(½ of 10 seconds); Vi=-50)

Using science to analyze nature

adds depth to our understanding and therefore adds to our appreciation of nature

A rock is thrown vertically into the air. At the very top of its trajectory the net force on it is

almost equal to its weight.

The maximum acceleration of a car while towing a second car twice its mass, compared to its acceleration with no car in tow, is

one third

The brakes of a speeding truck are slammed on and it skids to a stop. If the truck were heavily loaded so that it had twice the total mass, the skidding distance would be

same

A truly educated person is knowledgeable about

science, the arts, and religion

Two factors that greatly affect air resistance on falling objects are the

size and speed of the object

The statement, "There are regions beneath Earth's crust that will always be beyond the reach of scientific investigation," is a

speculation

If experimental findings are not reproducible,

the results are not considered valid

Drop a rock from a 5-m height and it accelerates at 10 m/s2 and strikes the ground 1 s later. Drop the same rock from a height of 2.5 m and its acceleration of fall is about

the same amount

The synthesis of a large collection of information that contains well-tested and verified hypotheses about certain aspects of the world is known as a scientific

theory

An object is propelled along a straight-line path by a force. If the net force were doubled, the object's acceleration would be

twice as much

While an object near the Earth's surface is in free fall, its

velocity increases

A scientific hypothesis may turn out to be right or it may turn out to be wrong. If it is a valid hypothesis, there must be a test for proving it

wrong

A car maintains a constant velocity of 100 km/hr for 10 seconds. During this interval it acceleration is

zero

A 1-kg ball is thrown at 10 m/s straight upward. Neglecting air resistance, the net force that acts on the stone when it is halfway to the top of its path is about

10

If a projectile is fired straight up at a speed of 10 m/s, the time it takes to reach the top of its path is about

1 second

If a car accelerates from rest at 2 meters per second per second, its speed 3 seconds later will be about

6 m/s

A 10-N block and a 1-N block lie on a horizontal frictionless table. To provide them with equal horizontal acceleration, we would have to push with

B) 10 times as much force on the heavier block.

Which of the following involves passion, talent, and intelligence?

art, literature, music, science

If an object moves with constant acceleration, its velocity must

change by the same amount each second

The scientific method is a method for

gaining new knowledge

A automobile and a baby carriage traveling at the same speed collide head-on. The impact force is

greater on the automobile & greater on the baby carriage

A skydiver's terminal velocity will be greatest if she falls

head first

In science, an educated guess is a

hypothesis

In science, an educated guess is called a

hypothesis

A bullet is fired straight down from the top of a high cliff. Neglecting air resistance, the acceleration of the bullet in meters per second per second

is 9.8

A bullet is dropped into a river from a very high bridge. At the same time, another bullet is fired from a gun, straight down towards the water. Neglecting air resistance, the acceleration just before striking the water

is the same for each bullet

Whenever the net force on an object is zero, its acceleration

is zero

A pair of tennis balls fall through the air from a tall building. One of them is filled with lead pellets. The ball to reach the ground first is the

lead-filled ball

A ball is thrown upwards and caught when it comes back down. In the presence of air resistance, the speed with which it is caught is always

less than the speed it had when thrown upwards

A skydiver falls towards the Earth. The attraction of the Earth on the diver pulls the diver down. What is the reaction to this force?

none of these