Answer:
Explanation:
Given
Apparent frequency
Velocity of sound
speed of observer
Using Doppler effect Apparent frequency when source is approaching is given by
Apparent frequency when source moves away from observer
Divide 1 and 2 we get
Thus speed of sound of police car is 40 m/s
KE = 1/2mv²
= 1/2(100)(4.0²)
KE = 800 J
hope this helps :)
Answer:
a) 0.64 b) 2.17m/s^2 c) 8.668joules
Explanation:
The block was on the ramp, the ramp was inclined at 20degree. A force of 5N was acting horizontal to the but not parallel to the ramp,
Frictional force = horizontal component of the weight of the block along the ramp + the applied force since the block was just about move
Frictional force = mgsin20o + 5N = 6.71+5N = 11.71
The force of normal = the vertical component of the weight of the block =mgcos20o = 18.44
Coefficient of static friction = 11.71/18.44= 0.64
Remember that g = acceleration due to gravity (9.81m/s^2) and m = mass (2kg)
b) coefficient of kinetic friction = frictional force/ normal force
Fr = 0.4* mgcos 20o = 7.375N
F due to motion = ma = total force - frictional force
Ma = 11.71 - 7.375 = 4.335
a= 4.335/2(mass of the block) = 2.17m/s^2
C) work done = net force *distance = 4.335*2= 8.67Joules
The atomic number of an element is the number of protons the element has, so the element with the atomic number 55 has 55 protons.
That's a not-bad description of a capacitor.