Answer:
a)1815Joules b) 185Joules
Explanation:
Hooke's law states that the extension of a material is directly proportional to the applied force provided that the elastic limit is not exceeded. Mathematically;
F = ke where;
F is the applied force
k is the elastic constant
e is the extension of the material
From the formula, k = F/e
F1/e1 = F2/e2
If a force of 60N causes an extension of 0.5m of the string from its equilibrium position, the elastic constant of the spring will be ;
k = 60/0.5
k = 120N/m
a) To get the work done in stretching the spring 5.5m from its position,
Work done by the spring = 1/2ke²
Given k = 120N/m, e = 5.5m
Work done = 1/2×120×5.5²
Work done = 60× 5.5²
Work done = 1815Joules
b) work done in compressing the spring 1.5m from its equilibrium position will be gotten using the same formula;
Work done = 1/2ke²
Work done =1/2× 120×1.5²
Works done = 60×1.5²
Work done = 135Joules
Answer:
3.33 minutes (3 minutes and 20 seconds)
Explanation:
Speed of the runner = s = 5 m/s
We need to calculate how will it take for runner to complete 1 km. We have the speed, the distance and we need to find the time. Before performing any calculations, we must convert the values to same units.
Speed is in m/s and distance is in kilometers. So we have to either convert speed to km/s or distance into meters. In this case, converting distance into meters would be a convenient option.
1 kilo meters = 1000 meters
The distance, speed and time are related by the equation:
Distance = Speed x Time
So,
Time = Distance/Speed
Using the values, we get:
t = 1000/5
t = 200 seconds
This means, the runner can complete 1 kilometers in 200 seconds. Since, there are 60 seconds in a minute, we can convert this time to minutes, by dividing it by 60. i.e.
Thus, it will take the runner 3.33 minutes (3 minutes and 20 seconds) to travel 1 km.
As we know that here no air resistance while ball is moving in air
So here we will say that
initial total energy = final total energy
here we know that
(as it will be on ground at initial and final position)
so we will say
since mass is always conserved
so we will say that final speed of the ball must be equal to the initial speed of the ball
so we have
1. Radio waves are generated by a transmitter and detected by a reciever. The reciever then encodes the radio wave into information to transport into your radio. You may have listened to either AM or FM radio.
2. Cell phones creates up and down sounds with the microphone. The microchip inside the phone turns those up and down sounds into numbers, and sends it off to the cell tower. The cell tower processes those numbers and sends it off to the phone you are trying to call.
3. The television service delivers programming to viewers by relaying information to communications satellites that can be found orbiting the earth. The satellite receiver decodes the programming to the viewer’s TV.
