Answer:
D
A machine can help decrease the input force and increase the output force.
Answer: Friction is the resistance to motion of one object moving relative to another. For example, when you try to push a book along the floor, friction makes this difficult. Force: Force is essentially a push, or a pull action, that can lead to certain outcomes.
Answer:
The minimum frequency is 702.22 Hz
Explanation:
The two speakers are adjusted as attached in the figure. From the given data we know that
=3m
=4m
By Pythagoras theorem

Now
The intensity at O when both speakers are on is given by

Here
- I is the intensity at O when both speakers are on which is given as 6

- I1 is the intensity of one speaker on which is 6

- δ is the Path difference which is given as

- λ is wavelength which is given as

Here
v is the speed of sound which is 320 m/s.
f is the frequency of the sound which is to be calculated.

where k=0,1,2
for minimum frequency
, k=1

So the minimum frequency is 702.22 Hz
Answer:
given , v = 300 km/hr; distance d = 1500 km; then time t = d/v = 1500/300 = 5 hrs
Explanation:
Answer:
Stellar black holes form when the center of a very massive star collapses in upon itself.