Children are sled riding on a hill One little girl pulls her sled back up the hill and does 379.5 joules of work while pulling i
1 answer:
Answer:
2.2N
Explanation:
Given parameters:
Work done = 379.5J
Height = 173m
Unknown:
Amount of force exerted on the sled = ?
Solution:
The amount of force she exerted on the sled is the same as her weight.
Work done is the force applied to move a body through a distance.
Work done = mgh
m is the mass
g is the acceleration due to gravity
h is the height
mg = weight;
Work done = weight x h
379.5 = weight x 173
weight = = 2.2N
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The correct choice is
D. 22 Hz and 42 Hz.
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In this problem, the beat frequency is , therefore the only pair of frequencies that gives a difference equal to 20 Hz is
D. 22 Hz and 42 Hz.
Answer:
The rock's final speed at the required altitude will be 42.24 m/s.
Explanation:
Let's start by finding the initial vertical speed.
Vertical Speed = 1.61 * Sin (53.2°)
Vertical Speed = 0.8 m/s
We want to know the speed of the rock when it is at an altitude of 91 km.
The total displacement of the rock from its starting position will thus be equal to -91 km
We can use this in the following equation:
t = 4.3918 seconds
Thus it takes 4.3918 seconds to reach the required altitude. We can now find the speed as follows:
Thus the rock's final speed at the required altitude will be 42.24 m/s.