Answer: <u>Option A: </u>The gas and food are examples of energy.
Explanation:
Work and energy are inter-related. Energy is required to do the work. An equal amount of energy is converted into work. Work and energy have same units. The SI unit is Joule.
The gas and food are sources of energy. They act as fuel. This energy is utilized to perform work. The gas is used to run the car. The food is metabolized inside the body which is a source of energy and utilized to perform every day work.
Hence, The gas and food are examples of energy.
Work done is given by the change in kinetic energy of an object
- The kinetic energy of the shovel, the shrub, and in Robert's movement were changed, therefore, work is done in the given processes,
Reason:
Work is done when the total energy of object is affected by the application of force on the object over a distance
Therefore;
- In option <em>A</em>, pushing the shovel into ground (to dig out the dirt) the requires the application of a force (push) over a distance, (into and out of the ground) therefore work is done
- In option <em>B</em>, picking the shrub up gives it gravitational potential energy, therefore, work is done
- In option <em>C</em>, carrying the shrub to the hole does visible work
- In option <em>D</em>, holding the shrub while lowering it into the hole does work by preventing the shrub from falling randomly
Therefore, <u>work is done in the given processes</u>
Learn more about work-energy theorem here:
brainly.com/question/10063455
Thomson experiment he calculated the charge to mass ratio just be passing the fundamental charge through a tube
He calculated the charge to mass ratio just by finding the deflection of charge while it is passing through the constant electric field
so here we will use the deflection as following
let say it passes the field of length "L"
so here we have
now in the same time if it deflect by some distance
now by solving this equation we can find e/m ratio
so here correct answer will be
the electron's charge-to-mass ratio
Answer:
(a) 0.942 m
(b) 18.84 m/s
(c) 2366.3 m/s²
(d) 0.05 s
Explanation:
(a) In one revolution, it travels through one circumference, 2πr = 2 × 3.14 × 0.15 m = 0.942 m.
(b) Its frequency, f, is 1200 rev/min = 
rev/s = 20 rev/s.
Its angular frequency, ω = 2πf = 2π × 20 = 40π
The speed is given by
v = ωr = 40π × 0.15 = 6π = 18.84 m/s
(c) Its acceleration is given by, a = ω²r = (40π)² × 0.15 = 2366.3 m/s²
(d) The period is the inverse of the frequency because it is the time taken to complete one revolution.
T = 1/20 = 0.05 s
Walking at a speed of 2.1 m/s, in the first 2 s John would have walked
(2.1 m/s) (2 s) = 4.2 m
Take this point in time to be the starting point. Then John's distance from the starting line at time <em>t</em> after the first 2 s is
<em>J(t)</em> = 4.2 m + (2.1 m/s) <em>t</em>
while Ryan's position is
<em>R(t)</em> = 100 m - (1.8 m/s) <em>t</em>
where Ryan's velocity is negative because he is moving in the opposite direction.
(b) Solve for the time when they meet. This happens when <em>J(t)</em> = <em>R(t)</em> :
4.2 m + (2.1 m/s) <em>t</em> = 100 m - (1.8 m/s) <em>t</em>
(2.1 m/s) <em>t</em> + (1.8 m/s) <em>t</em> = 100 m - 4.2 m
(3.9 m/s) <em>t</em> = 95.8 m
<em>t</em> = (95.8 m) / (3.9 m/s) ≈ 24.6 s
(a) Evaluate either <em>J(t)</em> or <em>R(t)</em> at the time from part (b).
<em>J</em> (24.6 s) = 4.2 m + (2.1 m/s) (24.6 s) ≈ 55.8 m
