Answer:
We need to multiply 12 to each term to eliminate fractions.
Explanation:
Given expression:
To eliminate the fraction we need to multiply each term by least common multiple of the denominators of the fraction.
The denominators in the above expressions are:
4, 3 and 2
The multiples of each can be listed below.
2⇒ 2,4,6,8,10,<u>12</u>,14,16.....
3⇒ 3,6,9,<u>12</u>,15,18
4⇒ 4,8,<u>12</u>.......
From the list of the multiples stated, we can see the least common multiple is 12.
So we will multiply each term by 12.
Multiplying 12 to both sides.
Using distribution,
Thus we successfully eliminated the fractions.
Answer:
Explanation:
We can try writing the equation of the horizontal component of the length of the minute hand in terms of distance and the angle, that depends of time in this particular case.
The x-component of the length of the minute hand is:
(1)
- d is the length of the minute hand (d=D/2)
- D is the diameter of the clock
- t is the time (min)
Now, using the angular kinematic equations we can express the angle in term of angular velocity and time. As we know, the minute hand moves with a constant angular velocity, so we can use this equation:
(2)
Also we know, that the minute hand moves 90 degrees or π/2 rad in 15 min, so using the definition of angular velocity, we have:
Now, let's put this value on (2)
Finally the length x(t) of the shadow of the minute hand as a function of time t, will be:
I hope it helps you!
Answer:
a. Springs oscillate with the same frequency
Explanation:
As they both are in the same height at equilibrium, so
weight of ball must be balanced with spring force, that is
k×x=mg
k= stiffness constant of spring
x=distance stretched
g= acceleration due to gravity
so, we can write
k/m=g/x
as the g is a constant and they stretched to same distance x so the g/x term becomes constant and
and k/m is same for both the springs so they will oscillate at the same frequency.
hence option a is correct.
Answer:
57.6Joules
Explanation:
Rotational kinetic energy of a body can be determined using the expression
Rotational kinetic energy = 1/2Iω²where;
I is the moment of inertia around axis of rotation. = 5kgm/s²
ω is the angular velocity = ?
Note that torque (T) = I¶ where;
¶ is the angular acceleration.
I is the moment of inertia
¶ = T/I
¶ = 3.0/5.0
¶ = 0.6rad/s²
Angular acceleration (¶) = ∆ω/∆t
∆ω = ¶∆t
ω = 0.6×8
ω = 4.8rad/s
Therefore, rotational kinetic energy = 1/2×5×4.8²
= 5×4.8×2.4
= 57.6Joules
Answer:
To increase kinetic friction, the amount of fine water droplets sprayed before the game is limited.
To reduce kinetic friction. increase the amount of fine water droplets during pregame preparation and sweeping in front of the curling stones.
Explanation:
In curling sports, since the ice sheets are flat, the friction on the stone would be too high and the large smooth stone would not travel half as far. Thus controlling the amount of fine water droplets sprayed before the game is limited pregame is necessary to increase friction.
On the other hand, reducing ice kinetic friction involves two ways. The first way is adding bumps to the ice which is known as pebbling. Fine water droplets are sprayed onto the flat ice surface. These droplets freeze into small "pebbles", which the curling stones "ride" on as they slide down the ice. This increases contact pressure which lowers the friction of the stone with the ice. As a result, the stones travel farther, and curl less.
The second way to reduce the kinetic friction is sweeping in front of the large smooth stone. The sweeping action quickly heats and melts the pebbles on the ice leaving a film of water. This film reduces the friction between the stone and ice.
