Relatively hot objects emit visible light.
Some examples:
==> the wire coils in the toaster;
==> the spoon that you stuck in the flame on the stove;
==> the fine wire in the lightbulb when current goes through it.
VERY radioactive objects also do that. But if you're actually
standing there watching an object that's THAT radioactive,
then you're in big trouble.
Answer:
The angular acceleration is 10.10 rad/s².
Explanation:
Given that,
Mass of sphere =220 g
Diameter = 4.50 cm
Friction force = 0.0200 N
Suppose we need to find its angular acceleration.
We need to calculate the angular acceleration
Using formula of torque


Here, I = moment of inertia of sphere


Put the value into the formula


Hence, The angular acceleration is 10.10 rad/s².
v₀ = initial velocity of the mobile = 10 m/s
v = final velocity of the mobile = 20 m/s
a = acceleration of the mobile = 5 m/s²
d = distance traveled during this operation = ?
Using the kinematics equation
v² = v²₀ + 2 a d
inserting the above values in the equation
20² = 10² + 2 (5) d
400 = 100 + 10 d
subtracting 100 both side
400 - 100 = 100 - 100 + 10 d
300 = 10 d
dividing both side by 10
300/10 = 10 d/10
d = 30 m
hence mobile travels 30 m.
Answer:
The net power needed to change the speed of the vehicle is 275,000 W
Explanation:
Given;
mass of the sport vehicle, m = 1600 kg
initial velocity of the vehicle, u = 15 m/s
final velocity of the vehicle, v = 40 m/s
time of motion, t = 4 s
The force needed to change the speed of the sport vehicle;

The net power needed to change the speed of the vehicle is calculated as;
![P_{net} = \frac{1}{2} F[u + v]\\\\P_{net} = \frac{1}{2} \times 10,000[15 + 40]\\\\P_{net} = 275,000 \ W](https://tex.z-dn.net/?f=P_%7Bnet%7D%20%3D%20%5Cfrac%7B1%7D%7B2%7D%20F%5Bu%20%2B%20v%5D%5C%5C%5C%5CP_%7Bnet%7D%20%3D%20%5Cfrac%7B1%7D%7B2%7D%20%5Ctimes%2010%2C000%5B15%20%2B%2040%5D%5C%5C%5C%5CP_%7Bnet%7D%20%3D%20275%2C000%20%5C%20W)
We know that a wave is a disturbance that transfers energy through matter or space There are two main types of waves: Mechanical and Electromagnetic. Water waves are mechanical. A mechanical wave is an oscillation of matter to transfers energy, but you always need a medium (substance such as: solid, liquid, gas, plasma) to transport it. The medium for water waves is, in fact, the water. For example, ripple in water is a surface wave. On the other hand, electromagnetic waves don't need a medium to transport, they can do it through the empty space. Then, this is the major characteristic that makes these two types of waves different.