Electron<span>. the central part of an atom containing </span>protons<span> and </span>neutrons<span> ... which of the following is necessary to calculate the atomic </span>mass<span> of an element? ... which of the </span>statements correctly compares<span>the relative size of an ion to its neutral atom?</span>
Explanation:
2) C would need the least effort, because the longer the effort distance, the least the effort applied.
The ratio of the distance moved by the point at which the effort is applied in a simple machine to the distance moved by the point at which the load is applied, in the same time. In the case of an ideal (frictionless and weightless) machine, velocity ratio = mechanical advantage. Velocity ratio is sometimes called distance ratio.
Answer:
v = 87.57 m/s
Explanation:
Given,
The initial velocity of the car, u = 0
The final velocity of the car, v = 60 mi/hr
The time period of car, t = 8 s
= 0.00222 hr
The acceleration of the car is given by the formula,
a = (v -u) / t
= 60 / 0.00222
= 27027 mi/hr²
If the car has initial velocity, u = 50 mi/hr
The time period of the car, t = 5.0 s
= 0.00139 hr
Using first equations of motion
<em> v = u + at</em>
= 50 + (0.00139 x 27027)
= 87.57 mi/hr
Hence, the final velocity of the car, v = 87.57 mi/hr
M = 7.0 kg, the mass of the groceries
h = 1.2 m, the elevation of the bag of groceries
The bag of groceries moves a constant velocity over the 2.7-m room.
At constant velocity, there is no applied force, and the kinetic energy remains constant.
At an elevation of 1.2 m, there is an increase in PE (potential energy) given by
V = m*g*h
= (7.0 kg)*(9.8 m/s²)*(1.2 m)
= 82.32 J
The change in PE is equal to the work done.
Answer: 82.3 J
