Answer:
a) v= 2.1 m/s
b) ω = 0.807 rad/s
Explanation
Conceptual analysis :
The dog and the merry-go- round describes a circular motion, then, the following formulas apply :
Formula (1)
v = ω *r Formula (2)
Where:
: Centripetal acceleration(m/s²)
v: linear speed or tangential (m/s)
r : radius of the circle (m)
ω : angular speed ( rad/s)
Data
r= 2.6 m
= 1.7 m/s²
Problem develpment
a) We replace data in the formula 1 to calculate the dog's linear speed(v):
v= 2.1 m/s
b)We replace data in the formula 2 to calculate the angular speed of the merry-go- round (ω).
v = ω *r
2.1 = ω *2.6
ω = 2.1/2.6
ω = 0.807 rad/s
Answer:
23 J
Explanation:
According to the law of conservation of energy, the total heat given off to the surroundings by a refrigerator is equal to the work done by the refrigerator and the heat removed from the inside of the refrigerator.
So we can write:
where
is the heat removed from the cold reservoir (the inside of the refrigerator)
W is the work done
is the work released into the hot reservoir (the surroundings)
Here we have:
(heat removed from the inside of the refrigerator)
(heat released into the surroundings)
Solving the equation for W, we find the work done:
Answer:
0.001 s
Explanation:
The force applied on an object is equal to the rate of change of momentum of the object:
where
F is the force applied
is the change in momentum
is the time interval
The change in momentum can be written as
where
m is the mass
v is the final velocity
u is the initial velocity
So the original equation can be written as
In this problem:
m = 5 kg is the mass of the fist
u = 9 m/s is the initial velocity
v = 0 is the final velocity
F = -45,000 N is the force applied (negative because its direction is opposite to the motion)
Therefore, we can re-arrange the equation to solve for the time:
<span>I believe the answer is 0.29.</span>
The mathematical definition of work (W) is force (F) multiplied by distance (x). In order to determine the distance for fixed force and work the above equation needs to be rearranged to make x the subject. The work divided by the force is equal to the distance. In this case the mother can push the baby carriage by a distance equal to 2920 divided by 62, which is 47.1 metres.
