Ask question

Ask question

All categories

3 years ago

12

Which of the following statements is true?

2 answers:

erica [24]3 years ago

6 0

An object at rest has an instantaneous acceleration of zero is true.

Option B

<u>Explanation</u>:

As we all know, acceleration is given by a, and formula is F/m, where F is force applied and m is mass of an object. Considering Instaneneous acceleration, it means the force per unit mass body is feeling during infinitesimally small time. Let us say 1 microsecond, acceleration of the body during that span of time is known as instanteneous acceleration. Considering option A, it might not be always true, as consider a vehicle going in straight direction, speed is changing and not direction. Option D is not again true, as consider earth rotating around sun, direction is changing but not speed. However, as explained above, instantaneous acceleration is always constant, and hence, body at rest have instantaneous acceleration zero.

rosijanka [135]3 years ago

3 0

The correct answers would be B, and d

You might be interested in

A motorcyclist changes the velocity of his bike from 20.0 meters/second to 35.0 meters/second under a constant acceleration of 4

Fiesta28 [93]

35-20 = 15m/s difference
15/4 = 3.75 seconds

4 0

3 years ago

Difference between derived quantity and physical quantity

Lerok [7]

Answer:

<h2>Derived quantities are based on fundamental quantities, and they can be given in terms of fundamental quantities.</h2>

<h3>Fundamental quantities are the base quantities of a unit system, and they are defined independent of the other quantities. </h3>

Explanation:

#Let's Study

#I Hope It's Helps

#Keep On Learning

#Carry On Learning

$\\ \blue{MaggieEve}$

6 0

2 years ago

A small loop of area A = 5.5 mm2 is inside a long solenoid that has n = 919 turns/cm and carries a sinusoidally varying current

Tema [17]

Answer: $410.90\times 10^{-6} V$

Explanation:

Given

$A=5.5 mm^2$

$n=919 turns/cm\approx 85400 turns/m$

$\omega =226 rad/s$

According to the Faraday law of induction, induced emf is given by

$E=-\frac{\mathrm{d} \phi _B}{\mathrm{d} t}$

Magnetic field $\phi _B=B\cdot A$

$B=\mu _0ni=\mu _0ni_osin\left ( \omega t\right )$

$B=4\pi \times 10^{-7}\times 85400\times 3.08\times \sin (226t)$

$B=0.3305\sin (226t)$

$\phi _{B}=0.3305\times \sin (226t)\times 5.5\times 10^{-6}$

$\phi _{B}=1.818\times 10^{-6}\sin (226t)$

$E=-\frac{\mathrm{d} \phi _B}{\mathrm{d} t}$

$E=-1.818\times 10^{-6}\times 226\cos (226t)$

$E=-410.90\times 10^{-6}\cos (226t)$

Amplitude of EMF induced $=410.90\times 10^{-6} V$

8 0

4 years ago

The law of reflection states that if the angle of incidence is 39 degrees, the angle of reflection is ___ degrees.

marishachu [46]

It's 39 degrees, too

good luck

8 0

3 years ago

A car is travelling at 18m/s accelerates ti 30m/s in 3seconds. what's the acceleration of the car

Luden [163]

Answer: a = 4 m/s²

Explanation:

a = Δv/t = (30 - 18) / 3 = 4 m/s²

3 0

3 years ago