Answer:
New gravitational force, F' = 216 units
Explanation:
Given that,
Gravitational force between object 1 and 2, F = 72 N
The gravitational force between two objects is given by :

............(1)
If the mass of object 1, 

If the distance between objects is halved, 
Let new gravitational force is F'. It is changed to :





F' = 216 units
So, the new gravitational force will be 216 units.
Answer:
359 m/s
Explanation:
Highest frequency a person can hear is 20,000Hz.
f = c × λ
Frequency = Wave speed × Wavelength
Wavelength = 20,000 ÷ 343 = 58.31m
Wavespeed = Frequency ÷ Wavelength
c = 20,950 ÷ 58.31 = 359.3 m/s
= 359 m/s (3 s.f.)
Answer:
raise the board to a higher angle
Explanation:
Static friction is the force opposite to the applied force.
Static friction is dependent on the angle of inclination, it means as the angle of incline increases, the force of friction will increases as normal force will decrease.
So, if the board will be raised to a higher angle, it will increase the angle of incline and will overcome the static friction and block will be able slide.
Hence, the correct option is "raise the board to a higher angle".
Answer: A
After rocks are eroded the particles turn into a sedimentary rock.
#1
As we know that energy of electromagnetic wave is given by

so here we know that penetrating power will directly depends on its energy and energy inversely depends on wavelength
So here we can say correct answer will be
C) The penetrating power decreases as the wavelength increases.
#2
Speed of sound is maximum in solids and minimum in gas
so here as ice melts into water the speed of sound must have to decrease
so correct answer will be
D) The speed of sound would decrease because sound travels faster through solids than liquids.
#3
mechanical waves required medium to travel while non mechanical waves do not require any medium to travel
so here correct answer will be
A) sound