The driver of a 1500 kg car, travelling on a highway, hits the brakes. A force of 12000 N stops the car in a distance of 64 m. how fast was the car going when the driver hit the brakes?
Answers
Answer:
Explanation:
As per work energy theorem we know that work done by all the forces must be equal to change in kinetic energy of the car
So here when brakes are applied then work is done by the brakes which is equal to change in kinetic energy of the car
so we know that work done by the brakes is given as
now we will have
Related Questions
do you think that this method of identifying unknowns would be effective for identifying any unknown element?
According to Faraday's law, voltage cannot be changed by changing the magnetic field strength.
The method of heat transfer by which the sun warms the earth isA) conduction B) convection C) radiation D) solaration
The four giant gas planets that are made primarily of lightweight elements areA. Earth, Saturn, Neptune, and Venus.B. Venus, Saturn, Uranus, and Neptune.C. Mercury, Venus, Earth, and Neptune.D. Jupiter, Saturn, Uranus, and Neptune.
Answers
Answer:
v = R w
With this expression we see that for each point at different radius the tangential velocity is different
Explanation:
They indicate that the angular velocity is constant, that is
w = dθ / dt
Where θ is the radius swept angle and t the time taken.
The tangential velocity is linear or
v = dx / dt
Where x is the distance traveled in time (t)
In the definition of radians
θ = s / R
Where s is the arc traveled and R the radius vector from the pivot point, if the angle is small the arc (s) and the length (x) are almost equal
θ = x / R
We substitute in the speed equation
v = d (θ R) / dt
The radius is a constant for each point
v = R dθ / dt
v = R w
With this expression we see that for each point at different radius the tangential velocity is different
Answers
V_xf = V_xi + a_x(t)
V_xf = 20.0m/s
V_xi = 0m/s
ax = 2.0t
Thus, solve for t and get 10secondsand then take 5 seconds to break after 20 seconds of drivingso for
a) 10 + 20 + 5 = 35 seconds
for part b)
You can use the formula
Delta x/Delta t = average velocity
Need to find xf, knowing xi = 0
Thus, use the formula
x_f = x_i + V_xi(t) + (1/2)a_x(t)^(2)
x_f = 0 + 0(10) + (1/2)(2.0)(10)^(2)
x_f = 100m
so for the first 10 seconds the truck traveled 100msAt a speed of 20m/s
20m/s = xm/20s20*20 = x
x = 400
thus we have 100+400 = 500mthen it slows down from 500m to x_f
thus I use the equation
x_f = x_i + (1/2)(V_xf + V_xi)t
x_f = 500 + (1/2)(0 + 20)(5)x_f = 500 + 50
x_f = 550
therefore the total distance traveled is 550m
to calculate average velocity
550/35 = 16m/s
thusV_xavg = 16m/s
B.The pressure of the water decreases.
C.The flow rate of the water decreases.
D.The density of the water increases.
Answers
The flow rate of the water decreases as the cross section is decreases. So, the correct option is C.
What is Bernoulli's equation?
Bernoulli’s principle states that the total mechanical energy of a moving fluid, which includes the gravitational potential energy of height, the energy associated with fluid pressure, and the kinetic energy of fluid motion, remains constant.
The formula for Bernoulli’s principle is given as follows:
From the equation of continuity for incompressible fluids which is Bernoulli's equation
a v = constant
where, a is the area and v is the velocity.
Pressure is inversely proportional to the velocity.
From the image we can see that area of cross-section at A is greater than at B,
thus,
which means velocity of water will increase at B and water pressure will decrease.
Hence, the correct option is C, i.e. the flow rate of water decreases.
Learn more about Bernoulli's equation, here:
#SPJ2
C. The flow rate of the water decreases
b. Kepler.
c. Copernicus.
d. Newton.
Answers
Answers
K E= m g h
h = 10 m, d = 5 m.
m g ( h + d ) - F d = 0
m g ( h + d ) = F d
70 * 9.8 * 15 = F * 5
10,290 = 5 F
F = 10,290 : 5
F = 2,058 N
First, we need to calculate the total distance that the diver travelled. The diver jumped off a 10-meter tower and went 5 meters under the water. Therefore, the total distance travelled by the diver is 10 meters (from the tower) plus 5 meters (underwater), which equals 15 meters.
Next, we will determine the work done on the diver. The work done is equal to the change in potential energy, which can be calculated by multiplying the diver's mass by gravity and then by the total distance the diver travelled. Given that the diver's mass is 70kg and the acceleration due to gravity is 9.8m/s², the work done is 70kg * 9.8m/s² * 15m, which equals 10290 Joules.
Finally, we'll find the average resistance force exerted on the diver by the water. The work done on the diver is also equal to the average force times the distance. Therefore, the average force is the work done divided by the distance. When you divide the work done (10290 Joules) by the total distance travelled (15 meters), you get an average force of 686 Newtons.
Hence, the total distance travelled by the diver in water is 5 meters, the work done on the diver is 10290 Joules, and the average resistance force exerted on the diver by the water is 2058 Newtons.
Learn more about Average resistance force exerted by water on a diver here:
#SPJ11
Particles of matter are packed more tightly in the ground than in the air.
Air doesn’t contain any particles of matter to transmit sound waves.
The elevation of the ground is lower than the elevation of the air space.
Answers
Answer:
Particles of matter are packed more tightly in the ground than in the air.
Explanation:
As we know that velocity of sound in a given medium is given by formula
here we know that
E = elasticity of the medium
= density of the medium
now we know that if we increase the density of medium then particles of matter are packed more which will decrease the speed of wave.
while is particles are tightly packed then it will increase the elasticity of the medium
So here if all particles are tightly bounded with each other then sound waves will move faster through the medium