Answer:
20cm
Explanation:
A convex lens has a positive focal length and the object placed in front of it produce both virtual and real image <em>(image distance can be negative or positive depending on the nature of the image</em>).
According to the lens equation
where;
f is the focal length of the lens
u is the object distance
v is the image distance
If the magnification is - 0.6
mag = v/u = -0.5
v = -0.5u
since v = 10cm
10 = -0.5u
u = -10/0.5
u =-20 cm
Substitute u = -20cm ( due to negative magnification)and v = 10cm into the lens formula to get the focal length f

Hence the focal length of the convex lens is 20cm
Answer:
B. 6.6%
Explanation:
The percentage error of a measurement can be calculated using the formula;
Percent error = (experimental value - accepted value / accepted value) × 100
In this question, the calibrated 250.0 gram mass is the accepted value while the weighed mass of 266.5 g is the experimental or measured value.
Hence, the percentage error can be calculated thus;
Percent error = (266.5-250.0/250.0) × 100
Percent error = 16.5/250 × 100
Percent error = 0.066 × 100
Percent error = 6.6%
Answer:
Explanation:
Given
mass of skier=60 kg
distance traveled by skier=75 m
inclination
speed (v)=2.4 m/s
as the skier is moving up with a constant velocity therefore net force is zero

Force applied by cable

work done

(b)Power

Answer:
The scientific questions here are:
<em>a) How will climate change affect forests</em>
<em>b) How did life on Earth begin</em>
<em>c) Why did dinosaurs go extinct</em>
Explanation:
Scientific question are logical quantifiable questions, whose answers can be measured. A good scientific question must have answers that can be tested by a carefully designed experiment or measurement. Some qualities like "prettiest" and "amazing" cannot be tested for nor are they measurable, and hence, they do not make a testable component of good scientific question.
Answer:
false
Explanation:
a tsunami is almost always caused by an earthquake under water.