A flashing red traffic light at an intersection means

I WILL GIVE BRAINLIEST!!!!

MAVERICK [17]

Answer:

His machine must increase

Explanation:

6 0

2 years ago

Read 2 more answers

A stone is thrown upward from the top of a building at an angle of 30° to the horizontal and with an initial speed of 20 m/s. Th

Hitman42 [59]

Answer:

Explanation:

Given

inclination $\theta =30^{\circ}$

initial speed $u=20\ m/s$

Point of release is 45 m above the ground

Considering stone to be a projectile, so time taken by projectile for its zero vertical displacement is

$t_1=\frac{2u\sin \theta }{g}$

$t_1=\frac{2\times 20\times \sin 30}{10}$

$t_1=2\ s$

Now after completing zero vertical displacement , stone needs to travel another 45 m in downward direction with initial speed u=20\sin 30

$h=u_yt+\frac{1}{2}a_yt^2$

where, $h=height$

$u_y=vertical velocity$

$a_y=vertical acceleration$

$t_0=time$

$45=20\sin 30+\frac{1}{2}(9.8)(t_0)^2$

$t_0^2=\frac{70}{9.8}$

$t_0=2.64\ s$

thus total time time required is $t=t_0+t_1=2.64+2=4.64\ s$

vertical velocity just before hitting

$v_y=\sqrt{u_y^2+2\times a_y\times s}$

$v_y=\sqrt{10^2+2\times 10\times 45}$

$v_y=\sqrt{1000}=31.622\ m/s$

Horizontal velocity $v_x=u\cos 30=17.32\ m/s$

Net velocity Just before hitting $=\sqrt{v_x^2+v_y^2}$

$=\sqrt{(17.32)^2+(31.62)^2}$

$=\sqrt{1299.82}=36.05\ m/s$

7 0

3 years ago

If a car is accelerating downhill under a net force 3674 N , what additional force would cause the car to have a constant veloci

Semenov [28]

Answer:

For the car to move with constant velocity the additional force required is $F__{dg} }= -3674 \ N$

Explanation:

From the question we are told that

The net force of the car is $F_{net} = 3674 \ N$

Generally the total force acting on the car is the net force plus the force due to gravity acting in direction of the car (Let denote it as $F__{dg}$ )

So the total force acting on the car is mathematically represented as

$F_{net} + F__{dg}} = F$

Here this F representing the total force can be mathematically represented as

$F = ma$

Now for constant velocity to be attained, the acceleration of the car will be zero

So at constant velocity

$F = m * 0$

=> $F = 0 \ N$

So

$F_{net} + F__{dg}} = 0$

=> $F__{dg} }= -F_{net}$

=> $F__{dg} }= -3674 \ N$

6 0

2 years ago

A wheel of radius 30 cm is rotating at a rate of 2.0 revolutions every 0.080 s. (A) through what angle, in radians, does the whe

ioda

You said 2 revolutions every 0.08 seconds

1 revolution = 2pi radians.

A). The 'unit rate' is (2 rev) x (2pi / 0.08 sec) = 50pi radians/sec. =

   157.1 radians per sec (rounded)

B). Radius of the wheel = 30 cm
   Circumference = 2pi R = 60pi cm = 188.5 cm (rounded)

   Rotation speed = 2 revs per 0.08 sec
   Linear speed = 2 x 60pi cm per 0.08 sec

   (120pi cm) / (0.08 sec) = 47.12 meters per sec

C). Frequency = (revs) per second

      = (2) / (0.08 sec) = 25 per second .

7 0

2 years ago

Pls answer 9 Through 12

belka [17]

Answer:

physics,chemistry,biology,astronomy and earht sciences

principles of science are integrity of knowledge honesty,collegiality(cooperation between colleagues) objectivity and openness

examples of science are actually branches of science so those are biology,mathematics,chemistry and physics etc

science is importent to provide our basic needs and to improve our living standard.It makes our life much easier by providing different technologies.It helps in the diagnosing and treatment of a disease

4 0

3 years ago