<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:
Option (a) is correct
Explanation:
The acceleration of an object is defined as the rate of change of velocity. Mathematically, it can be written as :
Where
v and u are final and initial velocity
It is clear that if there is some change in velocity, it means the object is experiencing either acceleration or deceleration. Hence, the correct option is (a).
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The actual mechanical advantage of a pulley is 2. The pulley has 3 supporting strings. What is the efficiency of the pulley?
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KGUS eNotes educator | CERTIFIED EDUCATOR
Hello.
The efficiency of a simple machine can be expressed as the ratio of the actual mechanical advantage divided by the theoretical mechanical advantage. You were given the actual mechanical advantage as 2, so you only need to determine the theoretical mechanical advantage. With a pulley system, this becomes a simple matter of determining how many strings support the pulley, which was nicely given as three. Therefore, the efficiency in this case is 2/3, or about 67%.
Answer:
4th of August is the
Explanation:
5th and then I can help out by getting
Explanation:
If the distance between the bottom of the ladder and the wall is x, then:
cos θ = x / 10
Taking derivative with respect to time:
-sin θ dθ/dt = 1/10 dx/dt
Substituting for θ:
-sin (acos(x / 10)) dθ/dt = 1/10 dx/dt
Given that x = 6 and dx/dt = 1.1:
-sin (acos(6/10)) dθ/dt = 1/10 (1.1)
-0.8 dθ/dt = 0.11
dθ/dt = -0.1375
The angle is decreasing at 0.1375 rad/s.