Understanding that stars are naturally quite hot, imagine I pulled a piece of hot iron from a furnace. It would glow a bright red, and then slowly fade to black as the iron cools.

White dwarfs glow for the same reason - they are HOT!

3 0

3 years ago

A ball is projected upward at time t = 0.0 s, from a point on a roof 70 m above the ground. The ball rises, then falls and strik

pentagon [3]

Answer:

The velocity of a ball will be "-70.13 m/s".

Explanation:

The given values are:

u = 70 m

t = 0.0 s

g = a = -9.8 m/s²

s = -1 m

v = ?

As we know,

The equation of motion will be:

⇒ $v^2-u^2=2as$

On substituting the estimated values, we get

⇒ $v^2-(70)^2=2\times (-9.8)\times (-1)$

⇒ $v^2-4900=19.6$

⇒ $v^2=19.6+4900$

⇒ $v^2=4919.6$

⇒ $v=\sqrt{4919.6}$

⇒ $v=70.13 \ m/s$

In downward direction, it will be:

⇒ $v=-70.13 \ m/s$

8 0

3 years ago

A uniform magnetic field B=5.210 T is perpendicular to the plane of the paper (into the page). The current-carrying wire of valu

ehidna [41]

Answer:5.21 N

Explanation:

Given

B=5.210 T

I=2 A

L=0.5 m

Given Wire is perpendicular to Magnetic field

$\theta =90^{\circ}$

$F=IL\times B$

$F=BIL sin\theta$

$F=5.210\cdot 2\cdot 0.5 sin(90)$

F=5.210 N

as 1 Tesla =1 N/A/m

4 0

3 years ago