Explanation:
<u>Formula:</u>

<u>d = distance given</u>
<u>t</u><u> </u><u>=</u><u> </u><u>the amount of time </u><u>given</u>
<u>Substitute the given values into the formula for velocity</u><u>:</u>

velocity is shortened for v.
8 (distance) divided by 4 (time) equals the velocity.
<u>Solve:</u>

The velocity of the toy car equals: B. 2 m/s.
Answer:
The correct answer is B.
The astronaut will know due to the light from the explosion.
Explanation:
Sound and vibrations require a medium such as air to travel through. Space, there is no air. Only a vacuum. So sound and vibrations are unable to travel. Light requires no medium to travel. It can go through a vacuum.
Therefore the Astronaut will see a bright flash of light as it travels from the explosion to outer space. It is also important to note that light can travel very far because nothing else interacts with its wave particles and as such, it cannot be impeded.
Cheers!
Answer:
Magnetic field experienced = 4.5 × 10⁻⁴ T
Explanation:
The magnetic field around an infinite straight current-carrying wire at a distance r from the wire is given by
B = (μ₀I)/(2πr)
B = ?
I = 20 KA = 20000 A
r = 8.9 m
μ₀ = magnetic permeability = 1.257 × 10⁻⁶ T.m/A
B = (1.257 × 10⁻⁶ × 20000)/(2π×8.9) = 4.5 × 10⁻⁴ T
Answer:
Option B
Explanation:
The correct answer is Option B
After leaving the spoon of copper , steel and wooden in the soup for several minute chef can grab Wooden spoon with bare hand.
Wooden material are insulator of heat means heat does not transfer through the wooden material.
where as heat transfer take place in steel as well as copper and chef will not be able to lift the spoon bare hand.
Answer:
the required electrical power when the room air and surroundings are at 30°C.= 52.51822 Watt
Explanation:
Power required to maintain the surface temperature at 150°C from 20°C
P= εσA(T^4-t^4)
P= power in watt
ε= emissivity
A= area of surface
T= 150°C= 423 K
t= 20°C= 303K
/sigma= 5.67×10^{-8} watt/m^2K^4
putting vales we get

P=52.51822 Watt
the required electrical power when the room air and surroundings are at 30°C.= 52.51822 Watt