All categories

3 years ago

Which of the following statements are true?

Physics

2 answers:

8_murik_8 [283]3 years ago

7 0

Explanation:

inertia ...

you push or throw something, and you apply some force to it at that moment, but then it moves and keeps moving even long after you have no more connection to it, and no more force is applied to it.

please consider : we are only talking about moving. not about acceleration.

so, yes, (a) is true.

(d) is true.

Studentka2010 [4]3 years ago

3 0

Answer: a, c, d

Explanation: a is true because the object will continue to move even without any force because of inertia (so yh thats why a is true). c is true because an object can accelerate if a single force acts on it. to accelerate (not move), it needs a force to act on it

Would appreciate brainly <3

You might be interested in

Structures on a bird feather act like a diffraction grating having 7000 7000 lines per centimeter. What is the angle of the firs

Anestetic [448]

Answer:

θ = 28.9°

Explanation:

We are given;

Wavelength; λ = 602nm = 602 x 10^(-9) m

Lines per centimetre = 7000 /cm = 700000 /m

Thus, the distance between 2 adjacent lines is;

d = 1/700000 = 1.43 x 10^(-6) m

The angle at which diffracted light is formed is given by the formula

mλ = d sinθ

Where;

m is the mth order of the diffraction

λ is the wavelength of the incident light

d is the distance separating the centres of 2 adjacent slits

θ is the angle at which diffraction occurs

From the question, m is 1 because it says first order.

Thus, plugging in the relevant values into mλ = d sinθ, we have;

1 x 602 x 10^(-9) = 1.43 x 10^(-6) sinθ

sinθ = 602 x 10^(-9)/(1.43 x 10^(-6))

sinθ = 0.42098

θ = sin^(-1) 0.42098

θ = 28.9°

8 0

3 years ago

Scientists can use the location and depth of where a fossil is found to estimate the age of the fossil. To do this, they use

Roman55 [17]

Answer:

C the Law of Superposition

Explanation:

Basically the law of Superposition is applied in this regard. The law states that "the oldest layer is on the bottom and the youngest layer is on top".

When we find fossils at a particular depth we can relatively date a rock based on the strata we find them. A fossil in place in bottom beds will be older than the one in the topmost layer. Fossils also succeed one another in a definite pattern according to the principle of fossil and fauna succession.

7 0

3 years ago

Read 2 more answers

what is the kinetic energy of an object that has mass of 30 kilograms and move with a velocity of 20 m/s

kotegsom [21]

Kinetic Energy = 1/2 * m * v² 1/2 * 30 * 20² 1/2 * 30 * 400 12000/2 6000 J.

7 0

3 years ago

The tension in the rope is constant and equal to 40 N as the block is pulled. What is the instantaneous power (in W) supplied by

Eduardwww [97]

Complete Question:

A 10 kg block is pulled across a horizontal surface by a rope that is oriented at 60° relative to the horizontal surface.

The tension in the rope is constant and equal to 40 N as the block is pulled. What is the instantaneous power (in W) supplied by the tension in the rope if the block when the block is 5 m away from its starting point? The coefficient of kinetic friction between the block and the floor is 0.2 and you may assume that the block starting at rest.

Answer:

Power = 54.07 W

Explanation:

Mass of the block = 10 kg

Angle made with the horizontal, θ = 60°

Distance covered, d = 5 m

Tension in the rope, T = 40 N

Coefficient of kinetic friction, $\mu = 0.2$

Let the Normal reaction = N

The weight of the block acting downwards = mg

The vertical resolution of the 40 N force, $f_{y} = 40sin \theta$

$\sum f(y) = 0$

$N + 40 sin \theta - mg = 0\\N = -40sin60 + 10*9.81 = 0\\N = 63.46 N$

$\sum f(x) = 0$

$40 cos 60 - f_{r} - ma = 0\\ f_{r} = \mu N\\ f_{r} = 0.2 * 63.46\\ f_{r} = 12.69 N\\40cos 60 - 12.69-10a = 0\\7.31 = 10a\\a = 0.731 m/s^{2}$

$v^{2} = u^{2} + 2as\\u = 0 m/s\\v^{2} = 2 * 0.731 * 5\\v^{2} = 7.31\\v = \sqrt{7.31} \\v = 2.704 m/s$

Power, $P = Fvcos \theta$

$P = 40 *2.704 cos60\\P = 54.074 W$

7 0

3 years ago

two electronics students are discussing electrical units. student A says that electrical power is measured in units coulombs, st

Savatey [412]

The statements of both students are incorrect.

-- Electrical power, just like mechanical power, is expressed in units of watts.
-- 'Coulomb' is the unit of electrical charge.
-- '400 k ohms' means 400,000 ohms of resistance.
-- 'Volt' is the unit of electromotive force (or potential difference).

There are no 'following statements'.

All in all, a very disappointing question.

8 0

3 years ago