Which two options are examples of waves refracting?

You are driving at the speed of 33.4 m/s (74.7296 mph) when suddenly the car in front of you (previously traveling at the same s

romanna [79]

Answer:

Part a)

a = - 8.45 m/s/s

Part b)

$d = 66 m$

Part c)

$d = 14.16 m$

Explanation:

Part a)

when car apply brakes then the friction force on the car in front of us is given as

$F_f = \mu mg$

here we need to find deceleration due to friction

$a = \frac{F_f}{m}$

$a = -\mu g$

$a = -8.45 m/s^2$

Part b)

Braking distance of the car is the distance that it move till it stops

so we will have

$v_f^2 - v_i^2 = 2ad$

$0 - 33.4^2 = 2(-8.45)d$

$d = 66 m$

Part c)

Since we know that average reaction time for human is 0.424 s

now we know that during reaction time our car will travel at uniform speed

so we will have

$d = vt$

$d = (33.4) (0.424)$

$d = 14.16 m$

4 0

2 years ago

A 28 kg student stand on the surface of the Earth. What is the magnitude of the

Contact [7]

Answer:

F = 274.68[N]

Explanation:

The gravitational force is equal to the weight of a body, or this case that of a person. Weight can be calculated by means of the product of mass by gravitational acceleration. In this way we have the following equation:

$F=m*g$

where:

F = force or weight [N]

m = mass = 28 [kg]

g = gravity acceleration = 9.81 [m/s²]

Now replacing:

$F=28*9.81\\F=274.68[N]$

4 0

2 years ago

The mass of the uniform cantilever is 1100 kg. Determine the force on the beam at A. Determine the force on the beam at B. Use C

Mashcka [7]

Answer:

Force A=-−2,697.75 N

Force B=13, 488.75 N

Explanation:

Taking moments at point A, the sum of clockwise and anticlockwise moments equal to zero.

25 mg-20Fb=0

25*1100g=20Fb

Fb=25*1100g/20=1375g

Taking g as 9.81 then Fb=1375*9.81=13,488.75 N

The sum of upward and downward forces are same hence Fa=1100g-1375g=-275g

-275*9.81=−2,697.75. Therefore, force A pulls downwards

Note that the centre of gravity is taken to be half the whole length hence half of 50 is 25 m because center of gravity is always at the middle

8 0

2 years ago

Why does the moon's gravity have a greater effect on the earth's ocean than the sun.

White raven [17]

Answer:

Tides on our planet are caused by the gravitational pull of the Moon and Sun. Earth's oceans "bulge out" because the Moon's gravity pulls a little harder on one side of our planet (the side closer to the Moon) than it does on the other. The Sun's gravity raises tides, too, but lunar tides are twice as big.

4 0

3 years ago

Two light bulbs have resistances of 400 Ω and 800 ΩThe two light bulbs are connected in series across a 120- V line. Find the cu

Natasha2012 [34]

1) Current in each bulb: 0.1 A

The two light bulbs are connected in series, this means that their equivalent resistance is just the sum of the two resistances:

$R_{eq}=R_1 + R_2 = 400 \Omega + 800 \Omega=1200 \Omega$