The power of a machine depend on two factors are work and time.
Option C
<u>Explanation:</u>
In science, power defined as the amount of work done in a unit time. i.e. delivering work in a rate of time or energy supply, expressed in input of work or transmitted energy divided by the time interval (t) or W/t.
Example: Some work can be done in the long run with a low-power engine or in a short time with a motor with high performance. The equation for power can be given as
Answer: the answer is storing properly in refrigeration.
Explanation:
You said "<span>A rocket's acceleration is 6.0 m/s2.".
That just means that its speed increases by 6 m/s every second.
Whenever you look at it, its speed is 6 m/s faster than it was
one second earlier.
If it starts out with zero speed, then its speed is 6 m/s after 1 second,
12 m/s after 2 seconds, 18 m/s after 3 seconds . . . etc.
How long does it take to reach 42 m/s ?
Well, how many times does it have to go 6 m/s FASTER
in order to build up to 42 m/s ?
That's just (42/6) = 7 times.
Writing it correctly, with the units and everything, it looks like this:
(42 m/s) / (6 m/s</span>²)
= (42/6) (m/s) / (m/s²)
= (42/6) (m/s · s²/m)
= 7 seconds
<h2>
Answer:</h2>
0.126m
<h2>
Explanation:</h2>
According to Hooke's law, the force (F) acting on a spring to cause an extension or compression (e) is given by;
F = k x e -------------------(i)
Where;
k = the spring's constant.
From the question, the force acting on the spring is the weight(W) of the mass. i.e
F = W -----------------------(ii)
<em>But;</em>
W = m x g;
where;
m = mass of the object
g = acceleration due to gravity [usually taken as 10m/s²]
<em>From equation (ii), it implies that;</em>
F = W = m x g
<em>Now substitute F = m x g into equation(i) as follows;</em>
F = k x e
m x g = k x e ------------------(iii)
<em>From the question;</em>
m = m1 = 3.5kg
k = 278N/m
<em>Substitute these values into equation (iii) as follows;</em>
3.5 x 10 = 278 x e
35 = 278e
<em>Now solve for e;</em>
e = 35/278
e = 0.126m
Therefore, the distance the spring is stretched from its unstretched length (which is the same as the extension of the spring) is 0.126m
Answer:
Work done = -220,000 Joules.
Explanation:
<u>Given the following data;</u>
Mass = 1100kg
Initial velocity = 20m/s
To find workdone, we would calculate the kinetic energy possessed by the car.
Kinetic energy can be defined as an energy possessed by an object or body due to its motion.
Mathematically, kinetic energy is given by the formula;
Where,
- K.E represents kinetic energy measured in Joules.
- M represents mass measured in kilograms.
- V represents velocity measured in metres per seconds square.
Substituting into the equation, we have;
K.E = 220,000J
Therefore, the workdone to bring the car to rest would be -220,000 Joules because the braking force is working to oppose the motion of the car.
