The Geography
796 FOLLOWERS
The Geography- Geography Blog. Geography is the science that studies the lands, the features, the inhabitants, and the phenomena of the Earth.
The Geography
3M ago
Bats and dolphins use echolocation to navigate or the find food or to find their way without relying on sight. The frequencies they use are
A) supersonic
B) infrasonic
C) ultrasonic
D) microsonic
Answer:
C) ultrasonic
Both bats and dolphins use ultrasound with frequencies of about 50 kHz and above ..read more
The Geography
3M ago
Light and sound are both waves. You can see a ringing bell inside an evacuated glass container but you can not hear it. This is because
A) of resonance
B) light travels faster than sound
C) sound requires air to be transmitted and light does not
D) light passes through glass but sound does not
Answer:
C) sound requires air to be transmitted and light does not ..read more
The Geography
3M ago
How will the frequency of the sound used for echolocation affect the size of objects that can be detected? Will higher or lower frequencies allow for detection of smaller objects with echolocation?
Answer:
The wavelength of a wave determines how it will be reflected. The shorter wavelengths of higher frequencies mean that the echolocation of bats and dolphins help them identify more detail -- or smaller objects -- than would be possible with longer wavelengths or lower frequencies ..read more
The Geography
3M ago
If a Mack truck and Honda Civic have a head-on collision, upon which vehicle is the impact force greater? Which vehicle experiences the greater acceleration?
Answer:
The force will be the same on the two vehicles, according to Newton's Third Law. That means the Civic, with far less mass, will experience a much greater acceleration, according to Newton's Second Law ..read more
The Geography
3M ago
Two 100-N weights are attached to a spring scale as shown. Does the scale read zero, 100 N, or 200 N -- or some other reading?
Answer:
The scale reads the tension in the string. The tension in the string is 100 N. This is the force the string must exert up on either of the 100-N weights at either end of the string.
Nothing is moving, nothing is accelerating, so the net force on the spring is zero. Likewise, the net force on either of the 100-N weights is also zero. But that is another question. The spring scale does not measure the net force. The spring scale simply measures the tension, the ..read more
The Geography
3M ago
When you drop a rubber ball on the floor it bounces almost to its original height. What causes the ball to bounce?
Answer:
The floor exerts an upward force on the ball -- that stops the ball and gives it an acceleration upward.
This upward force from the floor will cause the ball to deform or change shape while it is in contact with the floor ..read more
The Geography
3M ago
What is the net force on a 1-kg laboratory cart which accelerates at 3 m/s²?
a) 3 N
b) 10 N
c) 30 N
d) 45 N
Answer:
a) 3 N
F = m*a
F = (1 kg)*(3 m/s²)
F = 3 N ..read more
The Geography
3M ago
What acceleration is produced if a net force of 500 N is applied to a 1000-kg car?
a) 10 m/s²
b) 5.0 m/s²
c) 2.0 m/s²
d) 0.5 m/s²
Answer:
d) 0.5 m/s²
F = m a
500 N = (1,000 kg) (a)
a = (500 N) / (1,000 kg)
a = 0.5 m/s ..read more
The Geography
3M ago
Kinematics is a description of motion. Motion was first well understood
a) by Aristotle and the ancient Greeks
b) by Ptolemy in Egypt
c) by Galileo in Italy
d) not until the beginning of the twentieth century
Answer:
c) by Galileo in Italy  ..read more
The Geography
3M ago
A force of 25.0 Newtons is applied so as to move a 5.0 kg mass a distance of 20.0 meters. How much work was done?
Answer:
W = F × d = 25 N × 20.0 m = 50 J ..read more