Answer:
The Heavier Firefighter
Explanation:
Generally, more massive objects will have more intertia than less massive objects. As such it takes more force to halt a more massive object if its moving at the same speed as a smaller object. This can also be thought of in the context of Newton's second law. The more force needed to accelerate an object means the more force the object will have.
Unfortunately, the given statements are missing from the problem. However, we can still determine the relationship between the electric force between two objects and the distance between them. The formula for the electric force is given below:
F = (k*Q1*Q2)/d^2
k is a constant, while Q1 and Q2 are the respective charges of the objects. F is force, while d is distance.
As seen in the formula, we can see that the electric force F is inversely proportional to the square of the distance between the two objects.
Answer:
Mass will not change based on location, while weight will change based on gravitational pull.
Explanation:
The formula for weight is mass*gravitational pull, hence weight changes based on gravitational pull
Answer:
<em>60008.4 J</em>
<em></em>
Explanation:
The mass of each kid = 30 kg
mass of the cart = 20 kg
The speed of the cart down the hill = 30 km/hr = 30 x 1000/3600 = 8.33 m/s
The height of the hill = 80 m
The potential energy of the boys at the top of the hill = mgh
where
m is the total mass of the kids and the cart = (30 x 2) + 20 = 80 kg
g is the acceleration due to gravity = 9.81 m/s^2
h is their height above the ground = 80 m (on the top of the hill)
substituting, we have
potential energy PE = 80 x 9.81 x 80 = 62784 J
At an instance at the bottom of the hill
their kinetic energy = 
where
v is their velocity = 8.33 m/s
m is their total mass = 80 kg
substituting, we have
kinetic energy KE = 
= 2775.6 J
Total work done on the cart is equal to the energy lost by the cart when it reached the bottom of the hill
work done by friction = PE - KE = 62784 - 2775.6 = <em>60008.4 J</em>
Answer: Contact force
a. Applying break in a vehicle.
d. The speed of ball rolling on ground is reduced
Non contact force
b. A coconut falling from a coconut tree.
c. The planets revolving around the sun.
Explanation:
The contact force is the force which exerts when one object or entity comes in contact with other object or entity. For example, on application of break the vehicle stops, the force is applied on the breaks to stop the vehicle. The ball rolling on the ground the speed reduces so the application of force on the ground also reduces.
The non contact force is the force one object exerts on the other without coming in direct contact with the other object. The force exerted by one object on other due to gravity is a non contact force. The coconut falling on the ground and planets revolving around the sun are examples of non contact force due to gravity.
