Answer:
A. a parked bus
Explanation:
Because a parked bus probably has the most mass out of these 4 and as we know, mass is that quantity that is solely dependent upon the inertia of an object. The more inertia that an object has, the more mass that it has. A more massive object has a greater tendency to resist changes in its state of motion.
Answer:
Explanation:
Given the following data;
Mass of child = 23 kg
Mass of bike = 5.5 kg
Velocity = 4.5 m/s
Momentum can be defined as the multiplication (product) of the mass possessed by an object and its velocity. Momentum is considered to be a vector quantity because it has both magnitude and direction.
Mathematically, momentum is given by the formula;
To find the momentum of each of them;
I. Momentum of the child
Momentum C = mass * velocity
Momentum C = 23 * 4.5
Momentum C = 103.5 Kgm/s
II. Momentum of the bike
Momentum B = mass * velocity
Momentum B = 5.5 * 4.5
Momentum B = 24.75 Kgm/s
Hence, we can deduce from the calculations that the momentum of the child is greater than that of the bike because of the higher mass possessed by the child.
<span>The
kinetic energy is the work done by the object due to its motion. It is
represented by the formula of the half the velocity squared multiply by the
mass of the object. In this problem, you have two vehicles, the other one is large and the
other one is small. Let us assume that they travel with the same velocity. Note
that the kinetic energy is proportional to the mass of the object. So when you
increase the mass of the other, it also increases the kinetic energy of that
object. The same holds true for the two vehicles. The larger the vehicle, its
kinetic energy is also large and therefore its stopping distance will be longer
than that of the smaller vehicle.</span>
Complete question is;
Shoveling snow can be extremely taxing since the arms have such a low efficiency in this activity. Suppose a person shoveling a sidewalk metabolizes food at the rate of 800 W. (The efficiency of a person shoveling is 3%.)
(a) What is her useful power output? (b) How long will it take her to lift 3000 kg of snow 1.20 m? (This could be the amount of heavy snow on 20 m of footpath.) (c) How much waste heat transfer in kilojoules will she generate in the process?
Answer:
A) P_out = 24 W
B) t = 1470 s
C) Q = 1140.72 KJ
Explanation:
We are given;
Input Power; P_in = 800 W
Efficiency; η = 3% = 0.03
A) Formula for efficiency is;
η = P_out/P_in
Making P_out the subject, we have;
P_out = η•P_in
P_out = 0.03 × 800
P_out = 24 W
B) We know that;
Power = work done/time taken
Thus;
P_out = mgh/t
We are given;
m = 3000 kg
h = 1.20 m
Thus, time is;
t = (3000 × 9.8 × 1.2)/24
t = 1470 s
C) amount of heat wasted is calculated from;
Q = (P_in - P_out)t
Q = (800 - 24) × 1470
Q = 1,140,720 J
Q = 1140.72 KJ
Energy cannot be created nor be destroyed
