Answer:
Ek = 1705.28 [J]
Explanation:
In order to solve this problem, we must remember that kinetic energy can be calculated by means of the following equation.

where:
m = mass [kg]
v = velocity [m/s]
Ek = kinetic energy [J] (Units of Joules)
<u>For the person running</u>
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<u />
<u />
<u>For the bullet</u>
<u />
<u />
<u />
<u />
<u />
The difference in Kinetic energy is equal to:
Ek = 2025 - 319.72
Ek = 1705.28 [J]
Answer:
The time taken by the car to accelerate from a speed of 24.6 m/s to a speed of 26.8 m/s is 0.84 seconds.
Explanation:
Given that,
Acceleration of the car, 
Initial speed of the car, u = 24.6 m/s
Final speed of the car, v = 26.8 m/s
We need to find the time taken by the car to accelerate from a speed of 24.6 m/s to a speed of 26.8 m/s. The acceleration of an object is given by :


t = 0.84 seconds
So, the time taken by the car to accelerate from a speed of 24.6 m/s to a speed of 26.8 m/s is 0.84 seconds. Hence, this is the required solution.
Answer:
D) The ball exerts a force on the wall and the wall exerts a force back.
Explanation:
Newton's third law of motion states that:
"When an object A exerts a force on another object B, then object B exerts an equal and opposite force on object A"
In this problem, we can identify (for instance) object A with tha ball and object B with the wall. Therefore, if we apply Newton's third law, we get:
The ball (object A) exerts a force on the wall (object B), therefore the wall (object B) exerts an equal and opposite force on the ball (object A). So, option D is the correct one.
Answer:
The value is 
Explanation:
From the question we are told that
The initial speed is 
Generally the total energy possessed by the space probe when on earth is mathematically represented as

Here
is the kinetic energy of the space probe due to its initial speed which is mathematically represented as
=>
=> 
And
is the kinetic energy that the space probe requires to escape the Earth's gravitational pull , this is mathematically represented as

Here
is the escape velocity from earth which has a value 
=> 
=> 
Generally given that at a position that is very far from the earth that the is Zero, the kinetic energy at that position is mathematically represented as

Generally from the law energy conservation we have that
So

=> 
=> 
=> 