Answer:
Acceleration = 3m/s^2
Displacement = 126 m
Explanation:
The velocity changed from 12 to 30 m/s in 6 seconds. Using the formula for acceleration we get
(30-12)/6= 18/6= 3m/s^2
Displacement is d=.5a*t^2+v0*t
Inputting acceleration, time, and velocity leaves us with
d=1.5 * 36 + 12 * 6 = 54 + 72 = 126 m
suitcase can be pushed to a distance of 0.35 m
Explanation:
Work done= Ff d
w= 670 J
Ff= force of friction
d= distance
force of friction is given by Ff=μ mg
μ= coefficient of friction=2.76
m=mass=71.5 kg
so Ff= (2.76) (71.5) (9.8)
Ff=1934 N
so W= Ff d
670= 1934 d
d=0.35 m
Answer:
P = 25299.75 watts
Since 80km/h is the average speed of 92km/h and 68km/h, the power (in watts) is needed to keep the car traveling at a constant 80 km/h is P = 25299.75 watts
Explanation:
Given;
Mass of car m = 1280kg
initial speed v1 = 92km/h = 92×1000/3600 m/s= 25.56m/s
Final speed v2 = 68km/h = 68×1000/3600 m/s= 18.89m/s
time taken t = 7.5s
Change in the kinetic energy of the car within that period;
∆K.E = 1/2 ×mv1^2 - 1/2 × mv2^2
∆K.E = 0.5m(v1^2 -v2^2)
Substituting the values, we have;
∆K.E = 0.5×1280(25.56^2 - 18.89^2)
∆K.E = 189748.16J
Power used during this Change;
Power P = ∆K.E/t
Substituting the values;
P = 189748.16/7.5
P = 25299.75 watts
Since 80km/h is the average speed of 92km/h and 68km/h, the power (in watts) is needed to keep the car traveling at a constant 80 km/h is P = 25299.75 watts
Answer:
a) 0.162 V/m
b) 0.54 nT
c) 22 kW
Explanation:
Given
Distance of flight, d = 20 km
Intensity of signal, I = 35.1 μW/m²
Magnitude of the electric component is gotten using the formula
E(m) = √(2Iμc), where
E(m) = √(2 * 35*10^-6 * 4*3.142*10^-7 * 3*10^8)
E(m) = √(2 * 35*10^-6 * 1.257*10^-6 * 3*10^8)
E(m) = √0.0264
E(m) = 0.162 V/m
Magnitude of magnetic component can be gotten by using the relation
B(m) = E(m) / c
B(m) = 0.162 / 3*10^8
B(m) = 5.4*10^-10
B(m) = 0.54 nT
Transmission power, P = IA
where A = 1/2 * 4πr²
P = 2Iπr²
P = 2 * 35*10^-6 * 3.142 * (10000)²
P = 2 * 35*10^-6 * 3.142 * 1*10^8
P = 21994 W
Thus, the transmission power is 22 kW
