Answer:
∆PE = 749.7 J
At 0.9 m high, PE = 793.8 J
At 1.75 m high, PE = 1543.5 J
Answer:
7.5 J
Explanation:
To answer the question given above, we need to determine the energy that will bring about the speed of 1 m/s. This can be obtained as follow:
Mass (m) = 15 Kg
Velocity (v) = 1 m/s
Energy (E) =?
E = ½mv²
E = ½ × 15 × 1²
E = ½ × 15 × 1
E = ½ × 15
E = 7.5 J
Therefore, to change the speed to 1 m/s, the employee must do a work of 7.5 J.
Answer:

Explanation:
At some distance from the Earth the force of attraction due to moon is balanced by the force due to Moon
so we will have

now we have


so we will have

Now by energy conservation



The power exerted by the cyclist is determined as 50 W.
<h3>
Average power exerted by the cyclist</h3>
The power exerted by the cyclist is calculated as follows;
P = FV
where;
- F is the applied force
- V is velocity
P = 20 x 2.5
P = 50 W
Thus, the power exerted by the cyclist is determined as 50 W.
Learn more about power here: brainly.com/question/25263760
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-- Gravity makes a falling object fall 9.8 m/s faster every second.
-- So, it reaches the speed of 30 m/s in (30/9.8) = 3.06 seconds after it's dropped.
-- The distance an object falls from rest is D = 1/2 (acceleration) (time)²
D = 1/2 (9.8 m/s²) (3.06 sec)²
D = (4.9 m/s²) (9.37 sec²)
<em>D = 45.8 meters</em>
Notice that we don't care how high the building is. The problem works just as long as the object can reach 30 m/s before it hits the ground. That turns out to be anything higher than 45.8 meters for the drop . . . maybe something like 13 floors or more.
Now I'll go a little farther for you ! Writing the last paragraph made me a little curious and uncomfortable. So I went and looked up the world's tallest buildings . . . and I found out that this problem could never happen !
The tallest building in the world now is the Burj Khalifa, in Dubai. It has 163 floors, and it's 828 meters high ! That's 2,717 feet. It's gonna be a long time before there's a building that's 1125 meters tall, like this problem says. That's close to 3700 feet . . . I've had flying lessons where I wasn't that far off the ground !