Answer:
Albert Einstein was from Germany he was born theoritical physicist, from childhood only he loved mechanical toys, he was highly gifted in Mathematics, He was a world citizen and a scientific genius too. His contribution were:
1) he developed the theory of relativity
2) he also discovered the process of nuclear fission
3)he developed the quantum theory of specific heat
4)theory of stimulated emission, on which laser device technology is based
5) law of photoelectric effect
hope it helped you :)
 
        
             
        
        
        
Answer:
 B. 2 m/s
 B. Acceleration = 4.05 m/s² and Tension = 297.5 N. 
Explanation:
A force is applied on a mass m whose acceleration is 4 m/s
Force = mass × acceleration
a = F/m = 4 m/s
4 m/s = F/m
F = 4 m/s (m)
If  Force of 2F is applied on a mass of 4m ; it acceleration is as follows:
2F/4 m = F/ 2m 
4m/s (m) / 2m = 2 m/s
a = 2 m/s
2.
Given that 
mass  = 30 kg
 = 30 kg
mass  = 50 kg
 = 50 kg
 = 0.1
 = 0.1
From the question; we can arrive at two cases;
That :
 ----- equation (1)
   ----- equation (1)
 ---- equation (2)
 ---- equation (2)
50 a = 50 g - T
30 a = T - 30 g sin 30 - 4 × 30 g cos 30
By summation 
80 a =![[ 50  - 30 * \frac{1}{2} - 0.1 *30* \frac{\sqrt{3}}{2}]](https://tex.z-dn.net/?f=%5B%2050%20%20-%2030%20%2A%20%5Cfrac%7B1%7D%7B2%7D%20-%200.1%20%2A30%2A%20%5Cfrac%7B%5Csqrt%7B3%7D%7D%7B2%7D%5D) g
g
80 a = 32. 4 × 10 m/s ²  (using g as 10m/s²)
80 a = 324 m/s ²
a = 324/80 
a = 4.05 m/s²
From equation , replace a with 4.05 
50 × 4.05 = 50 × 10 - T
T = 500 -202.5
T =297.5 N
 
        
             
        
        
        
Speed of wave = Frequency x Wavelength
so Speed = 0.7 x 9 = 6.3
remember the calculations must be done in their Basic SI units.
therefore, you have to convert 7 mm to meters which becomes 0.7 meters
        
             
        
        
        
B,a current flows through the wire
        
             
        
        
        
Answer:
Energy is defined as the ability to do work. Forms of energy could be kinetic energy or potential energy. Thermal or heat energy can originate from a hot object such as the sun. Energy is used to produce work. Electrical energy for lighting purposes and heating in homes and factories.
Explanation:
Energy is defined as the ability to do work and can be in various forms such as kinetic energy, potential energy, thermal, chemical, electrical energy etc.
Energy origination depends on the type of energy form in discussion. Thermal or heat energy can originate from a hot object such as the sun or an iron box, chemical energy originates from the interaction of atoms and molecules and electrical energy can be initiated by movements of electrons. 
Energy is used to produce work. Different forms of energy can do different tasks such as;
Heat energy for heating water 
Electrical energy for lighting purposes 
Geothermal energy for producing heat and electricity
Nuclear energy for production of nuclear power
Chemical energy for facilitating chemical reactions