Answer:
388.5J
Explanation:
Given parameters:
Weight = 70N
Height = 5.55m
Unknown:
Gravitational potential energy at the top of the ladder = ?
Solution:
The gravitational potential energy is the energy due to the position of the body.
Gravitational potential energy = Weight x height
So;
Gravitational potential energy = 70 x 5.55 = 388.5J
Answer: frequency is 20000hz
Explanation:
Velocity=340m/s
Wavelength=0.017m
Frequency=velocity ➗ wavelength
Frequency=340 ➗ 0.017
Frequency=20000hz
Answer:
The minimum velocity of the ball so the string will not go slack as the ball moves around the circle = 6.17 m/s
Explanation:
During the motion of the ball round the circle, the force keeping the ball in circular motion is directed towards the centre of the circle and the gravity is always pointing down.
At the highest position in the motion of the ball, the velocity is at a minimum because the net force responsible for motion is the difference between centripetal force (force in the string, keeping the ball in circular motion) and the weight of the ball.
At the bottom position of the ball, it has maximum velocity during the circular motion (net force = centripetal force + weight).
If the velocity of the ball is too low at the bottom, the ball will not have enough energy to make it to the top.
As the ball comes to the bottom of its circular motion, its kinetic energy increases because its potential energy is decreasing and as the ball moves back to the top of the circle of the circular motion, its kinetic energy decreases because its potential energy is increasing.
So, with respect to the height of the bottom of the circular motion as point 0, the diameter of the circular motion is the maximum vertical height reached by the ball.
And the minimum kinetic energy to still be able to rise to that vertical height = potential energy at that vertical height
(1/2) mv² = mgh
m = 0.167 kg
v = ?
g = 9.8 m/s²
h = 2 × radius = 2 × 0.97 = 1.94 m
(1/2) v² = 9.8 × 1.94
v² = 2×9.8×1.94 = 38.024
v = 6.17 m/s
(A) We can solve the problem by using Ohm's law, which states:
where
V is the potential difference across the electrical device
I is the current through the device
R is its resistance
For the heater coil in the problem, we know
and
, therefore we can rearrange Ohm's law to find the current through the device:
(B) The resistance of a conductive wire depends on three factors. In fact, it is given by:
where
is the resistivity of the material of the wire
L is the length of the wire
A is the cross-sectional area of the wire
Basically, we see that the longer the wire, the larger its resistance; and the larger the section of the wire, the smaller its resistance.
Light waves are electromagnetic waves while sound waves are mechanical waves. Light waves are transverse while sound waves are longitudinal. Light waves can travel in vacuum. Sound waves require a material medium to travel, and hence, cannot travel in vacuum.
They make use of radio waves. Radio waves signal are sent their headsets that in turn translates the signal in the form of sound. While communicating with people on Earth – the radio waves are transmitted which in turn are transformed to sound wave by a radio set. Radio waves comes from the light spectrum called Electromagnetic Spectrum and thus they are light waves. Unlike sound, light waves doesn’t need a medium to travel and it is for this reason that the sun ray travels through space to the Earth
We all know who was the first man that landed on moon? But were the first words ever heard in space?
It was the announcement of landing that was said by Neil Armstrong: “Lunar Module has landed on moon”
