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:
6480 km
Explanation:
The speed of the object is
v = 7500 cm/sec
We need to convert centimetres into kilometers and seconds into days. We have:
Using these conversion factors, we find:
Answer:
Workdone = 600 Kilojoules
Explanation:
Given the following data:
Time = 8 seconds
Power = 75,000 Watts
Distance = 58 m
To find the work done;
Power can be defined as the energy required to do work per unit time.
Mathematically, it is given by the formula;
Thus, work done is given by the formula;
Workdone = power * time
Workdone = 75000 * 8
Workdone = 600,000 = 600 KJ
Answer:
Only a decreasing gravitational force that acts downward
Explanation:
The gravitational force is the gravitational pull which attract a mass of smaller size by the mass of a bigger size. It is the force which attract two masses close to each other.
In the context, when a ball is tossed up from the surface of an asteroid that have no atmosphere, the ball rises up and then falls back to the surface of the asteroid. The ball falls back because the gravitational pull of the asteroid pulls back the ball to its surface. Thus a decreasing gravitational force acts on the ball in the downward direction while the ball is in its way up.
We will first convert all units to meters and then solve the problem.
We are given that:
1000 mm = 1 m
120 mm = ?? meters
using cross multiplication:
120 mm = (120*1) / 1000 = 0.12 m
Now, when the two objects are placed over each other, their total height is the result of summation of both heights, therefore:
total height = 0.12 + 1.5 = 1.62 m
Based on the above calculations, the correct choice is:
b) 1.62 m
