Answer:
Explanation:
1. Frictional force is responsible for running of car and buses on roads.
2.Gravitational force exists between astronauts in space.
3. Magnetic for is responsible to attract the iron objects using a magnet
4.Electrostatic force is responsible for fiber to stick on the skin.This force occurs due to the presence of charge.
5.When a person is pushing a trolley then object experience a normal reaction from ground.
6.Gravitational force makes the planet to move in their orbits.
 
        
             
        
        
        
Answer:
 is the rock's speed.
 is the rock's speed.
Explanation:
Momentum is defined as motion possessed by the moving body's mass. Mathematically it a product of mas and velocity of the body.

Given : Mass of rock = m = 1.45 kg
Velocity of the rock = v
Momentum of the rock = P =


 is the rock's speed.
 is the rock's speed.
 
        
             
        
        
        
Answer:b
Explanation: If you look at the line on the graph, you can see that it is going downward, meaning it has a negative slope, and choice b is the only one that has a negative slope
 
        
                    
             
        
        
        
Answer:
The direction of the field is downward, and negatively charged particles will experience an upwards force due to the field.
F = N e E     where E is the value of the field and N e the charge Q
M g = N e E      and M g is the weight of the drop
N = M g / (e E)
N = 1.1E-4 * 9.8 / (1.6E-19 * 370) = 1.1 * 9.8 / (1.6 * 370) * E15 = 1.82E13
.00011 kg is a very large drop
Q = N e = M g / E = .00011 * 9.8 / 370 = 2.91E-6 Coulombs
Check:     N = Q / e = 2.91E-6 / 1.6E-19 = 1.82E13   electrons
 
        
             
        
        
        
Answer:
The answer to your question: d.
Explanation:
a. The rate of change of momentum of an object is equal to the net force applied to the object.  
This is the second a law of motion, so this answer is incorrect.
b. In the absence of a net force acting on it, an object moves with constant velocity.
This is the first Newton law of motion, so this option is not correct.
c. For any force, there always is an equal and opposite reaction force.
This is the third law of motion, so this is not the right option.
d. What goes up must come down.
Newton said this sentence, but is not part of the law of motion.