Answer:
The mass of the child + skateboard is 50 kg
Explanation:
In this problem, we can apply Newton's second law:
F = ma
where
F is the net force on a system
m is the mass of the system
a is the acceleration of the system
In this problem, our system is the child + the skateboard. The net force on them is
F = 75 N
and their acceleration is
So we can re-arrange the equation above to find their combined mass:
Answer:
wrong statement : Momentum is not conserved for a system of objects in a head-on collision.
Explanation:
In a head on collision of two objects , two equal and opposite forces are created at the point of collision . These two forces create two impulses in opposite direction which results in equal and opposite changes in momentum in each of them . Hence net change in momentum is zero. In this way momentum is conserved in head on collision of two objects.
Answer:
A metalloid is used because it is a semiconductor and can become more conductive when more light shines on it
Explanation:
The material used in a solar panel is a metalloid. It can often become conductive when more light shines on it.
Metalloids have properties that straddles between those of metals and non-metals.
In essence, they can be conductive or not under certain conditions.
The most important property they exhibit is that they can become more conductive when more light shines on them. This way more electrons are produced.
Answer:
a) 24.4 Ω
b) 4.92 A
c) 495.9 W
d)
c. It will be larger. The resistance will be smaller so the current drawn will increase, increasing the power.
Explanation:
b)
The formula for power is:
P = IV
where,
P = Power of heater = 590 W
V = Voltage it takes = 120 V
I = Current Drawn = ?
Therefore,
590 W = (I)(120 V)
I = 590 W/120 V
<u>I = 4.92 A</u>
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a)
From Ohm's Law:
V = IR
R = V/I
Therefore,
R = 120 V/4.92 A
<u>R = 24.4 Ω</u>
<u></u>
c)
For constant resistance and 110 V the power becomes:
P = V²/R
Therefore,
P = (110 V)²/24.4 Ω
<u>P = 495.9 W</u>
<u></u>
d)
If the resistance decreases, it will increase the current according to Ohm's Law. As a result of increase in current the power shall increase according to formula (P = VI). Therefore, correct option is:
<u>c. It will be larger. The resistance will be smaller so the current drawn will increase, increasing the power.</u>
the sun was stationary in the center of the universe and the earth revolved around it....
