Answer:
b) 900 W
Explanation:
The breaker trips when the current is equal to 20 A. The power (P) is the ddp (V) multiplied by the current. So, for the electric heater, the current is:
P = V*i
1500 = 120*i
i = 12.5 A
So, to become in 20 A, it's needed 7.5 A, which must come from the hairdryer. Its power must be:
P = 120*7.5
P = 900 W
Answer:
Δ v = 125 m/s
Explanation:
given,
mass of space craft = 435 Kg
thrust = 0.09 N
time = 1 week
= 7 x 24 x 60 x 60 s
change in speed of craft = ?
Assuming no external force is exerted on the space craft
now,



a = 2.068 x 10⁻⁴ m/s²
using equation of motion
Δ v = a t
Δ v = 2.068 x 10⁻⁴ x 7 x 24 x 60 x 60
Δ v = 125 m/s
Answer:
M=28.88 gm/mol
Explanation:
Given that
T= 95 K
P= 1.6 atm
V= 4.87 L
m = 28.6 g
R=0.08206L atm .mol .K
We know that gas equation for ideal gas
P V = n R T
P=Pressure , V=Volume ,n=Moles,T= Temperature ,R=gas constant
Now by putting the values
P V = n R T
1.6 x 4.87 = n x 0.08206 x 95
n=0.99 moles
We know that number of moles given as

M=Molar mass


M=28.88 gm/mol
Solution :
The motion in the y direction.
The time taken by the toy rocket to hit the ground,

S = distance travelled = 30 m
u = 0 m/s
a = 
t= time in seconds
Therefore, 
t = 2.47 sec
Now motion in the x direction,
u = 12 m/sec

Upon integration 'v' with respect to 't'

Once again integrating with respect to t,


= 0.0176+29.64
= 29.65 m
Therefore, the toy rocket will hit the ground at 29.65 m from the building.
A heat pump is a device that puts out heat. It involves pumping a lever over and over to get energy so it can work.