Answer:
satellite B
Explanation:
A .F= G (mM)/r²
B .F= G (2mM)/r² = 2G (Mm)r²
C .F= G (3mM)/(2r)² = ¾G (mM)/r²
D .F= G (4mM)/(2r)² = G (mM)/r²
The answer is c) electromagnetic sawed in which the vibrations are perpendicular to the motion of the sound
Answer:
Answer D: It describes the relationship between motion and force.
Explanation:
The answer is D because a law is something that describes something in nature, but does not try to explain how or why is occurs (that is a theory). Options B and C sound more like theories, while option A sounds like a definition. Option D is correct because a law describes without explaining.
Answer:
The new period will be reduced by 50%
Explanation:
The period of pendulum is given by;

When the length is decreased by 25%, the new length L₂ is given by;
L₂ = 25/100(L₁)
L₂ = 0.25L₁

Thus, the new period will be reduced by 50%
Answer:
3.80 m/s
Explanation:
Solution: From the question we have:
A 2.10 x 10^3 kg car starts from rest at the top of a 5.0 m long driveway that is sloped at 20 degrees with the horizontal.
average friction force of 4.0 x 10^3 N impedes the motion
To find out: find the speed of the car at the bottom of the driveway.
=>h = 5×sin20 = 1.71 m.
PE = mgh = 2100×9.8×1.71 = 35,192 J.
KE = PE-work done by frictional force
KE=PE-4000×5
0.5mV^2 = 35192 - 4000×5
1050V^2 = 15,192
V^2 = 14.47
V = 3.80 m/s.