Answer:
The cost of using the hair dryer for 15 minutes is 
Explanation:
The parameters given in the question are;
The electric current drawn by the the air dryer, I = 11 A
The voltage to which the hair dryer is connected, V = 120 V
The duration of usage of the hair dryer = 15 minutes = 60 minutes /4 = 1 hour/4 = 0.25 hour
The electrical energy costs $0.09/kW·h
The power consumed by the hair dryer = I × V = 11 × 120 = 1320 Watts = 1.32 kW
The energy used by the hair dryer in 15 minutes (0.25 hour) = 1.32 × 0.25 0.33 kW·h
The energy used by the hair dryer in 15 minutes (0.25 hour) = 0.33 kW·h
The energy cost = $0.09/(kW·h)
Therefore;
The cost of using the hair dryer for 15 minutes (0.25 hour) = 0.33 kW·h/($0.09/(kW·h)) = $33/9 = $3 2/3 = $3.6
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Answer:
a) Frope= 71.7 N
b) Frope=6.7 N
Explanation:
In the figure the skier is simulated as an object, "a box".
a) At constant velocity we can say that the object is in equilibrium, so we apply the Newton's first law:
∑F=0
Frope=w*sen6.8°
Frope=71.71N
Take into account that w is the weight that is calculated as mass per gravitiy constant:
w=m*g


b) In this case the system has an acceleration of 0.109m/s2. Then, we apply Newton's second law of motion:
F=m*a
F=61.8Kg*0.109m/s2
Frope=6.73N
Answer:
Equal to change in momentum of larger mass.
Explanation:
We are given that
Two difference masses .
Force act on both masses for the same length of time.
We have to find the change in momentum of the smaller mass.
Let M and m are two masses
M>m
We know that
Change in momentum for large mass=
Change in momentum for small mass=
Because Force and length of time are same for both masses .
Hence, the change in momentum of smaller mass is equal to change in momentum of larger mass.