A simple machine can make work easier by reduce the amount of energy needed to perform a task, therefore, B. <span>it magnifies the potential energy so that the kinetic energy is greater</span> is the correct answer.
If you cannot get a chair to move across the floor, it is because static friction opposes your push. When you say static or kinetic friction the two object that facing each other are opposing each other. That's why you're having a hard time pushing the chair.
<h3>
Answer:</h3>
117.6 Joules
<h3>
Explanation:</h3>
<u>We are given;</u>
- Force of the dog is 24 N
- Distance upward is 4.9 m
We are required to calculate the work done
- Work done is the product of force and distance
- That is; Work done = Force × distance
- It is measured in Joules.
In this case;
Force applied is equivalent to the weight of the dog.
Work done = 24 N × 4.9 m
= 117.6 Joules
Hence, the work done in lifting the dog is 117.6 Joules
Answer:
1.86 m
Explanation:
First, find the time it takes to travel the horizontal distance. Given:
Δx = 52 m
v₀ = 26 m/s cos 31.5° ≈ 22.2 m/s
a = 0 m/s²
Find: t
Δx = v₀ t + ½ at²
52 m = (22.2 m/s) t + ½ (0 m/s²) t²
t = 2.35 s
Next, find the vertical displacement. Given:
v₀ = 26 m/s sin 31.5° ≈ 13.6 m/s
a = -9.8 m/s²
t = 2.35 s
Find: Δy
Δy = v₀ t + ½ at²
Δy = (13.6 m/s) (2.35 s) + ½ (-9.8 m/s²) (2.35 s)²
Δy = 4.91 m
The distance between the ball and the crossbar is:
4.91 m − 3.05 m = 1.86 m
Answer:
They will meet at a distance of 7.57 m
Given:
Initial velocity of policeman in the x- direction, ![u_{x} = 10 m/s](https://tex.z-dn.net/?f=u_%7Bx%7D%20%3D%2010%20m%2Fs)
The distance between the buildings, ![d_{x} = 2.0 m](https://tex.z-dn.net/?f=d_%7Bx%7D%20%3D%202.0%20m)
The building is lower by a height, h = 2.5 m
Solution:
Now,
When the policeman jumps from a height of 2.5 m, then his initial velocity, u was 0.
Thus
From the second eqn of motion, we can write:
![h = ut + \frac{1}{2}gt^{2}](https://tex.z-dn.net/?f=h%20%3D%20ut%20%2B%20%5Cfrac%7B1%7D%7B2%7Dgt%5E%7B2%7D)
![2.5 = \frac{1}{2}\times 10\times t^{2}](https://tex.z-dn.net/?f=2.5%20%3D%20%5Cfrac%7B1%7D%7B2%7D%5Ctimes%2010%5Ctimes%20t%5E%7B2%7D)
t = 0.707 s
Now,
When the policeman was chasing across:
![d_{x} = u_{x}t + \frac{1}{2}gt^{2}](https://tex.z-dn.net/?f=d_%7Bx%7D%20%3D%20u_%7Bx%7Dt%20%2B%20%5Cfrac%7B1%7D%7B2%7Dgt%5E%7B2%7D)
![d_{x} = 10\times 0.707 + \frac{1}{2}\times 10\times 0.5 = 9.57 m](https://tex.z-dn.net/?f=d_%7Bx%7D%20%3D%2010%5Ctimes%200.707%20%2B%20%5Cfrac%7B1%7D%7B2%7D%5Ctimes%2010%5Ctimes%200.5%20%3D%209.57%20m)
The distance they will meet at:
9.57 - 2.0 = 7.57 m