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
