Explanation:
Question 1
1.The wires are made of conducting materials e.g copper
2. A light bulb is made of filament material e.g tungsten with gases enclosed in a glass material
3.The lens is made of transparent glass material
4 The reflector is made of plastic with silver lining
5. The exterior casing of most flash lights are made of plastic
Question 2.
1.Copper is used to conduct electric current from the battery to the bulb
2.The tungsten filament ignite the gases and causes it to glow
3. The lens covers the lamp on your flashlight so that the glass on the lamp
/bulbs does not get broken.
4.The reflector redirects the light rays from the lamp, creating a steady beam of light, which is the light you see emitting from the flashlight.
5. The exterior cases houses the entire assembly and makes the flash light handy for use
complete question:
A child bounces a 60 g superball on the sidewalk. The velocity change of the superball is from 22 m/s downward to 15 m/s upward. If the contact time with the sidewalk is 1/800 s, what is the magnitude of the average force exerted on the superball by the sidewalk
Answer:
F = 1776 N
Explanation:
mass of ball = 60 g = 0.06 kg
velocity of downward direction = 22 m/s = v1
velocity of upward direction = 15 m/s = v2
Δt = 1/800 = 0.00125 s
Linear momentum of a particle with mass and velocity is the product of the mass and it velocity.
p = mv
When a particle move freely and interact with another system within a period of time and again move freely like in this scenario it has a definite change in momentum. This change is defined as Impulse .
I = pf − pi = ∆p
F = ∆p/∆t = I/∆t
let the upward velocity be the positive
Δp = mv2 - m(-v1)
Δp = mv2 - m(-v1)
Δp = m (v2 + v1)
Δp = 0.06( 15 + 22)
Δp = 0.06(37)
Δp = 2.22 kg m/s
∆t = 0.00125
F = ∆p/∆t
F = 2.22/0.00125
F = 1776 N
Answer:
satellite B
Explanation:
A .F= G (mM)/r²
B .F= G (2mM)/r² = 2G (Mm)r²
C .F= G (3mM)/(2r)² = ¾G (mM)/r²
D .F= G (4mM)/(2r)² = G (mM)/r²
Answer:
An engine with an electronic fuel injection system has high fuel pressure at idle because of high manifold vacuum. (option D)
Explanation:
Electronic fuel injection (EFI) system replaced carburetors back in the mid-1980s as the preferred method of supplying air and fuel to engines. The basic difference is that a carburetor uses intake vacuum and a pressure drop in the venturi, to siphon fuel from the carburetor fuel bowl into the engine. Whereas fuel injection system uses pressure to spray fuel directly into the engine.
However, under light load or at idle, a relatively high vacuum exists in the intake manifold. This means less fuel pressure is needed to spray a given volume of fuel through the injector. Under heavy load, engine vacuum drops to near zero.
Therefore, An engine with an electronic fuel injection system has high fuel pressure at idle because of high manifold vacuum.