D)sound waves the electromagnetic spectrum has to do with colors<span />
Answer:
0.976 c
Explanation:
= velocity of object 1 relative to earth = 0.80 c
= velocity of object 2 relative to object 1 = 0.80 c
= velocity of object 2 relative to earth
Velocity of object 2 relative to earth is given as
= 0.976 c
Answer: 
Explanation:
The density 
of a material is given by:
(1)
Where:
is the mass of the cube
is the volume of the cube
Now, the volume of a cube is equal to the length 
of its edge to the power of 3:
(2)
If we know 
, the volume of this cube is:
(3)
Substituting (3) in (1):
(4)
This is the density of the cube
Answer:
200 N
Explanation:
The crowbar is 2 meter, or 200 cm. The effort arm is 160 cm, so the moment arm of the object is 40 cm.
(800 N) (40 cm) = F (160 cm)
F = 200 N
Answer: 960 W
Explanation:
Power is the rate at which energy is dispensed. Electrical power can be defined as the rate at which electric energy is flowing in an electric circuit. It is given by the formula:
P = V I
Where, V is the voltage(V) , I is the current (A).
V = 240 V (given)
I = 4 A (given)
P = VI = 960 Watts
Hence, power used by the cloth dryer is 960 W.
