Answer: So if you are looking in your mirror in the car, you will clearly see what the vehicle is.
Explanation: When there are flashing lights and noises coming from behind you in a car, your first response is going to be checking your mirrors. When you look at the inverted "ambulance" you will see it correctly.
Answer:
Explanation:
Sun is the only source of heat on earth. Heat from sun first passes through atmosphere and then fall on the earth's surface i.e. land and ocean.
Condensation, Radiation, Convection, Conduction transfers heat within the atmosphere and ocean such as rise of hot air, cooling and then falling is the example of convection whereas, heat from fire is the example of radiation.
Answer:
20.9 m/s
Explanation:
Given that,
Initial velocity, u = 16 m/s
We need to find its velocity 0.5 s into flight when a ball straight up into the air. Let it is v. It will move under the action of gravity. Using first equation of motion to find it as follows :
v=u+at
Here, a = g
v = 16 + 9.8(0.5)
v = 20.9 m/s
So, the final velocity is 20.9 m/s.
Answer:
4.281 kgm/s upward
Explanation:
Impulse:This can be defined product of force and time. The S.I unit of impulse is Ns.
From Newton's second law of motion,
Impulse = Change in momentum.
I = mΔv....................... Equation 1.
Where m = mass of the ball, Δv = change in velocity of the ball
and Δv = v -u
Where u = velocity of the ball before it hit the floor, v = velocity of the ball after if hit the floor
I = m(v-u) -------------- Equation 2
But
the initial kinetic energy of the ball = potential energy at the initial height (1.2 m above)
1/2mu² = mgh₁
Where h₁ = initial height. or height of the ball before collision
making u the subject of the equation,
u = √(2gh₁)........................ Equation 3
Where h₁ = 1.2 m g = 9.81 m/s²
Substitute into equation 3
u = √(2×1.2×9.81)
u =√(23.544)
u = -4.852 m/s.
Note: u is negative because the ball was moving downward at the first instance.
Similarly,
v = √(2gh₂)............................. Equation 3
h₂ = height of the ball after collision
Given: h₂ = 0.7 m, g = 9.81 m/s²
Substitute into equation
v = √(2×9.81×0.7)
v = √13.734
v = 3.71 m/s.
Also given: m = 0.5 kg,
Substituting into equation 2
I = 0.5(3.71-(4.852)
I = 0.5(8.562)
I = 4.281 kgm/s. Upward.
Thus the impulse = 4.281 kgm/s upward
Answer:
Explanation
The most famous and common example is Christmas tree lights. You can't tell easily by looking at them whether they are in series or parallel. But you sure know the difference when one of them burns out. When that happens, the whole string goes dead. No matter what you do (other than find out which bulb burned out) will not fix the problem.
Another example is anything that is temperature controlled. For example a furnace is controlled by a thermostat. When the room temperature reaches a certain point, the thermostat is constructed in a certain way so that it forms an open circuit and no current can flow through it. The furnace motor turns off and the furnace stops pumping hot air into a room.