Answer:
F = 98.67 N
Explanation:
Given that,
The initial velocity of the sled, u = 1.6 m/s
The mass of the child and the sled is 37 kg
The sled stops pushing on it for 0.60s in a direction opposite to its motion.
We need to find the magnitude of the average force you need to apply to stop the sled.
Impulse = change in momentum
We have, v = 0
So, the magnitude of the average force is 98.67 N.
Answer: Albert Einstein
Explanation:
Light can be considered as a wave or as particles, in this context Einstein proposed that light behaves like a stream of particles called <u>photons</u> with an energy, in order to correctly explain the photoelectric effect (in fact he won the 1921 Nobel Prize in Physics because of this explanation).
To uderstand it better:
The photoelectric effect is a fenomenom that consists in the emission of electrons that occurs when light falls on a metal surface under certain conditions.
This can only be explained based on the corpuscular model of light, that is, light is quantized.
So, Einstein theorized light as a stream of energy packets called photons, this energy is able to pull an electron out of the crystalline lattice of the metal and communicate, in addition, a kinetic energy.
Answer:
Pretty sure it's B. Oblique Lighting
Explanation:
A. is clearly wrong, C. is also clearly wrong, D and E both have nothing to do with lighting, Oblique Lighting is defined as "using a light source positioned at a low angle. Oblique lighting is usually used to show detail by creating shadows on the surface of the evidence." Hope this helps.
Answer and Explanation:
Stars create energy primarily through the fusion of hydrogen into helium through nuclear reactions.
Answer:
(a) 2 (b) 4 (c) 4
Explanation:
Significant figures : The figures in a number which express the value -the magnitude of a quantity to a specific degree of accuracy is known as significant digits.
Rules for significant figures:
- Digits from 1 to 9 are always significant and have infinite number of significant figures.
- All non-zero numbers are always significant. For example: 654, 6.54 and 65.4 all have three significant figures.
- All zero’s between integers are always significant. For example: 5005, 5.005 and 50.05 all have four significant figures.
- All zero’s preceding the first integers are never significant. For example: 0.0078 has two significant figures.
- All zero’s after the decimal point are always significant. For example: 4.500, 45.00 and 450.0 all have four significant figures.
- All zeroes used solely for spacing the decimal point are not significant. For example : 8000 has one significant figure.
As per question,
0.000054 has 2 significant figures.
3.001 x 10⁵ has 4 significant figures.
5.600 has 4 significant figures.
