A box of mass 3kg is lifted 1.5m onto a shelf. Calculate the change in its gravitational potential energy. The gravitational fie
1 answer:
Answer:
The change in gravitational potential energy is 45 J.
Explanation:
Given that,
Mass = 3 kg
Distance = 1.5 m
Gravitational field strength = 10 N/kg
We need to calculate the change in gravitational potential energy
Using formula of gravitational potential energy
Put the value into the formula
Hence, The change in gravitational potential energy is 45 J.
You might be interested in
Apparent frequency heard by the staff: 389 Hz
Explanation:
The phenomenon described in this situation is called Doppler effect.
Doppler effect occurs when there is a source emitting a wave in relative motion with respect an observer. In such situation, the frequency of the wave as perceived by the observer ("apparent frequency") is shifted from the real frequency of the sound ("proper frequency"). In particular:
- The observer perceives a higher frequency if the source is moving towards them
- The observer perceives a lower frequency if the source is moving away from them
The formula to calculate the apparent frequency in the Doppler effect is
where
f is the proper frequency
f' is the apparent frequency
v is the speed of the wave
is the velocity of the observer (positive if they are moving towards the source, negative if moving away)
is the velocity of the source (positive if it is moving away, negative if moving towards the observer)
First of all, in this problem we have to calculate the proper frequency of the sound wave emitted from the ambulance; we have:
v = 343 m/s (speed of sound wave)
(wavelength)
So the proper frequency is
Now we can calculate the apparent frequency heard by the staff at the hospital when the ambulance moves away; we have:
(velocity of the ambulance)
(velocity of the staff)
Substituting,
Learn more about frequency and wavelength:
#LearnwithBrainly
Answer:
Explanation:
Given
Em wave is in the form of
where
Wave constant for EM wave k is
Wavelength of wave