Friction is a force in which two objects _________

At the instant the traffic light turns green, an automobile starts with a constant acceleration a of 2.5 m/s2. At the same insta

Licemer1 [7]

Answer:

6.96 s

Explanation:

<u>Given:</u>

u = initial speed of the automobile = 0 m/s

a = constant acceleration of the automobile = $2.5\ m/s^2$
v = constant speed of the truck = 8.7 m/s

<u>Assume:</u>

t = time instant at which the automobile overtakes the truck.

At the moment the automobile and the truck both meat each other the distance travel by both vehicles must be the same.

$\therefore \textrm{Distance traveled by the automobile }=\textrm{Distance traveled by the truck}\\\Rightarrow ut+\dfrac{1}{2}at^2=vt\\\Rightarrow (0)t+\dfrac{1}{2}\times 2.5\times t^2=8.7t\\\Rightarrow 1.25t^2=8.7t\\\Rightarrow 1.25t^2-8.7t=0\\\Rightarrow t(1.25t-8.7)=0\\\Rightarrow t = 0\,\,\,or\,\,\, t = \dfrac{8.7}{1.25}\\\Rightarrow t = 0\,\,\,or\,\,\, t = 6.96\\$

Since t = 0 s is the initial condition. So, they both meet again at t = 6.96 s such that the automobile overtakes the truck.

6 0

2 years ago

Why is it important to know the direction of the force applied to a moving object and the direction in which the object is movin

erastova [34]

Answer

(C).

When there is an angle between the two directions, the cosine of the angle must be considered.

Step by step Solution

The work done by a force is defined as the product of the force and the distance traveled in the direction of motion.

The first answer "Only the component of the force perpendicular to the motion is used to calculate the work" is wrong because, the force perpendicular to motion does no work.

The second choice "If the force acts in the same direction as the motion, then no work is done" is wrong because the work in the direction of the force is $W=F\times d$ .

Fourth answer "A force at a right angle to the motion requires the use of the sine of the angle" is wrong because the $sin(90)=0$ meaning that there is no work done in the direction perpendicular to the motion.

The third answer" When there is an angle between the two directions, the cosine of the angle must be considered." is correct because the work is calculated using the force in the direction of the motion. The magnitude of this force is $F\times d\times \cos(\theta).$

4 0

3 years ago

Read 2 more answers

Joseph studied whether different materials can block certain electromagnetic waves by testing television reception in different

gizmo_the_mogwai [7]

Using the same antenna. Now he doesn't know if it was the antenna that caused the change in reception. so he wasn't only measuring the reception in his house he was measuring it based on different antennas

7 0

2 years ago

A space vehicle is traveling at 2980 km/h relative to Earth when the exhausted rocket motor is disengaged and sent backward. The

Strike441 [17]

Answer:

3054.4 km/h

Explanation:

Using the conservation of momentum

momentum before separation = 5M × 2980 Km/h where M represent the mass of the module while 4 M represent the mass of the motor

initial momentum = 14900 M km/h

let v be the new speed of the motor so that the

new momentum = 4Mv and the new momentum of the module = M ( v + 94 km/h )

total momentum = 4Mv + Mv + 93 M = 5 Mv + 93M

initial momentum = final momentum

14900 M km/h = 5 Mv + 93M

14900 km/h = 5v + 93

14900 - 93 = 5v

v = 2961.4 km/h

the speed of the module = 2961.4 + 93 = 3054.4 km/h

8 0

3 years ago

niobium metal becomes a superconductor when cooled below 9 k. its superconductivity is destroyed when the surface magnetic field

Furkat [3]

Niobium wire with a 2.60 mm diameter has a maximum current capacity of 500 A while still remaining superconducting.

<h3>Describe the present.</h3>

Current is the rate at which charge passes from one point on a circuit to another. In a circuit, a significant current flows when several coulombs or charge pass over the cross section of a wire. When the charge carriers are firmly packed inside the wire, high currents can be generated at low speeds.

<h3>What do current and electron actually mean?</h3>

Electron movement is referred to as electron current. The positive terminal receives electrons that are released by the negative terminal. Traditional current, usually referred to as just current, exhibits behavior consistent with positive charge carriers being the source of current flow. Regular current is received at the positive end and then flows to a negative terminal.

To know more about current visit:
brainly.com/question/15141911

#SPJ4

5 0

7 months ago

Friction is a force in which two objects __________.