Power (rate of using energy) = (voltage) x (current)
Power of this heating element = (120 V) x (3.2 A) = 384 watts
The easy way:
384 watts = 0.384 kilowatt
(0.384 kilowatt) x (5 hours) = 1.92 kilowatt-hour
Another way:
384 watts = 384 joules per second .
(384 joule/sec) x (3600 sec/hour) x (5 hours)
= (384 x 3600 x 5) (joules) = 6,912,000 joules.
Answer:
1.38 metres
Explanation:
Using the law of conservation of energy, the mechanical energy when leaving the ramp is same as mechanical energy when the skier is at the highest point
When leaving the ramp, sum of kinetic energy and potential energy will be
Ei=KEi+PEi where Ei is initial mechanical energy, KEi is initial kinetic energy and Pei is initial potential energy
KEi=
where v is the initial speed and m is mass
PEi=mgh but since h=0, PEi=0 where m is mass, g is gravitational constant and h is height
Therefore, Ei=KEi+PEi=
The mechanical energy of the skier at the highest point is given by
Ef=KEf+PEf where Ef is final energy, KEf is final kinetic energy and PEf is final potential energy
Ef=
Equating Ei=Ef then
98m= m(84.5+9.81h)
98-84.5=9.81h
h=13.5/9.81= 1.376147m
h=1.38 metres
Newton's 2nd law of motion:
Force = (mass) x (acceleration)
= (1,127 kg) x (6 m/s² forward)
= (1,127 x 6) newtons forward
= 6,762 newtons forward
______________________________
Momentum = (mass) x (speed)
= (69 kg) x (6 m/s)
= 414 kg-m/s
Answer:
Apparent depth (Da) = 60.15 cm (Approx)
Explanation:
Given:
Distance from fish (D) = 80 cm
Find:
Apparent depth (Da)
Computation:
We know that,
Refractive index of water (n2) = 1.33
So,
Apparent depth (Da) = D(n1/n2)
Apparent depth (Da) = 80 (1/1.33)
Apparent depth (Da) = 60.15 cm (Approx)