Answer:
720 J
Explanation:
The gravitational potential energy that Essam loses for every metre is given by:

where
m=72 kg is Essam's mass
is the gravitational field strength
is the difference in height
By substituting the numbers into the formula, we find

Answer:
8, 8 W
Explanation:
The useful power of 1 Light Emitting Diode is

Total power required is 1.6 W
Number of Light Emitting Diodes would be

The number of Light Emitting Diodes is 8.
Power would be

The power that is required to run the Light Emitting Diodes is 8 W
Answer:
630cm/s
Explanation:
In simple harmonic motion, the tangential velocity is expressed mathematically as v = ὦr
ὦ is the angular velocity = 2πf
r is the radius of the disk
f is the frequency
Given the radius of disk = 10cm
frequency = 10Hz
v = 2πfr
v = 2π×10×10
v = 200π
v = 628.32 cm/s
The tangential velocity = 630cm/s ( to 2 significant figures)
Answer:
b
Explanation:
he keep the thermoter in the water longer
<span>5.98 x 10^-2 ohms.
Resistance is defined as:
R = rl/A
where
R = resistance in ohms
r = resistivity (given as 1.59x10^-8)
l = length of wire.
A = Cross sectional area of wire.
So plugging into the formula, the known values, including the area of a circle being pi*r^2, gives:
R = 1.59x10^-8 * 3.00 / (pi * (5.04 x 10^-4)^2)
R = (4.77 x 10^-8) / (pi * 2.54016 x 10 ^-7)
R = (4.77 x 10^-8) / (7.98015 x 10^-7)
R = 5.98 x 10^-2 ohms
So that wire has a resistance of 5.98 x 10^-2 ohms.</span>