An ice cube would transfer heat to another object whose temperature
is lower than zero°C (32°F).
A block of "dry ice" is sitting there at a temperature of -78°C (-109°F).
An ice cube helps to melt dry ice nice and fast.
If you could find a block of solid nitrogen, its temperature would be
63K (-210°C, -346°F). An ice cube would transfer heat to that baby
so fast that it would instantly boil.
Answer:
(A) 3.1 m/s
(B) 2.0 s
Explanation:
At the minimum speed, the force of gravity equals the centripetal force.
mg = m v² / r
v = √(gr)
v = √(9.8 m/s² × 1.0 m)
v = 3.1 m/s
The time is the circumference divided by the speed.
t = (2π × 1.0 m) / (3.1 m/s)
t = 2.0 s
Answer:
maybe its heat sorry if it's wrong
because if friction is not in the problem so we are making heat or thermal energy
Answer:
The height of Sears Tower is 1448.5 feet.
Explanation:
<h3>
We apply the free fall formula to the ball:
</h3><h3>
</h3><h3>y: The vertical distance the ball moves at time t </h3><h3>
i: Initial speed
</h3><h3>g=Gravity acceleration=
</h3>
Known information
We know that the vertical distance (y) that the ball moves in 9,5s is equal to height of Sears Tower (h).
Too we know that the ball is released from rest, then,
=0
Height of Sears Tower calculation:
We replace in the equation 1 the data following;
Answer: The height of Sears Tower is 1448.5 ft
Answer:
S=48.29 m
Explanation:
Given that the height of the hill h = 2.9 m
Coefficient of kinetic friction between his sled and the snow μ = 0.08
Let u be the speed of the skier at the bottom of the hill.
By applying conservation of energy at the top and bottom of the inclined plane we get.
Potential Energy=kinetic Energy
mgh = (1/2) mu²
u² = 2gh
u²=2(9.81)(2.9)
=56.89
u=7.54 m/s
a = - f / m
a = - μ*m*g / m
a = - μg
From equation of motion
v²- u² = 2 -μ g S
v=0 m/s
-(7.54)²=-2(0.06)(9.81)S
S=48.29 m
