Answer: The answer in scientific notation with the unit included is (1 × 10^-3m.)
Explanation:
In the field of physics, when working with too large or too small numbers, such can be expressed with the use of scientific notation. This helps to eliminate huge or ambiguous numbers with significant units. It is written is such a way that the first number is greater than or equal to 1 and less than 10 which is then multiplied by a factor of 10.
Units are symbols that are used to represent a measurement For example the unit of meters is (m).
Converting 1mm to m:
1000millimeters = 1meter
1 millimetre = X
Making X the subject of formula,
X = 1 ×1 /1000
X = 0.001m
Therefore expressing X in scientific notation is
1 × 10^-3meter (m)
Answer:
0.2 J
Explanation:
The pendulum forms a right triangle, with hypotenuse of 50 cm and base of 30 cm. The height of this triangle can be found with Pythagorean theorem:
c² = a² + b²
(50 cm)² = a² + (30 cm)²
a = 40 cm
The height of the triangle is 40 cm. The height of the pendulum when it is at the bottom is 50 cm. So the end of the pendulum is lifted by 10 cm. Assuming the mass is concentrated at the end of the pendulum, the potential energy is:
PE = mgh
PE = (0.200 kg) (9.8 N/kg) (0.10 m)
PE = 0.196 J
Rounding to one significant figure, the potential energy is 0.2 J.
