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4 years ago

Can someone help me please it is number 7

Physics

1 answer:

motikmotik4 years ago

4 0

D. The string vibrated because of resonance, which happened because the tuning fork and guitar string have same natural frequency.

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A particular automotive wheel has an angular moment of inertia of 12 kg*m^2, and is decelerated from 135 rpm to 0 rpm in 8 secon

lozanna [386]

Answer:

(A) Torque required is 21.205 N-m

(b) Wok done will be equal to 1199.1286 j

Explanation:

We have given moment of inertia $I=12kgm^2$

Wheel deaccelerate from 135 rpm to 0 rpm

135 rpm = $135\times \frac{2\pi }{60}=14.1371rad/sec$

Time t = 8 sec

So angular speed $\omega _i=135rpm$ and $\omega _f=0rpm$

Angular acceleration is given by $\alpha =\frac{\omega _f-\omega _i}{t}=\frac{0-14.1371}{8}=--1.7671rad/sec^2$

Torque is given by torque $\tau =I\alpha$

$=12\times 1.7671=21.205N-m$

Work done to accelerate the vehicle is

$\Delta w=K_I-K_F$

$\Delta W=\frac{1}{2}\times 12\times 14.137^2-\frac{1}{2}\times 12\times0^2=1199.1286J$

8 0

4 years ago

Sara Lilia pulled out four different CD's to find out which type helped her to finish her

lord [1]

Step by step explanation

7 0

3 years ago

A car undergoing uniform acceleration travels 100 meters from a standing start in a given period of time. If the time were incre

iogann1982 [59]

Answer:

d = 1600 m

Explanation:

If car start from rest and accelerates uniformly then the displacement of the car is given as

$d = v_i t + \frac{1}{2}at^2$

now we know

$d = 0 + \frac{1}{2}at^2$

now if the same car will accelerate from rest for four times of the previous time interval

then we will have

$d = 0 + \frac{1}{2}a(4t)^2$

$d = 16(\frac{1}{2}at^2)$

so the distance will be 16 times more

$d = 1600 m$

5 0

4 years ago

_________ is the point on which a lever resets

Sergio [31]

Answer:

the answer is fulcrum because

Explanation:

lever is a simple machine consisting of a bar that rotates around a fixed point. The fixed point of a lever is called the fulcrum. Like other machines, a lever makes work easier by changing the force applied to the machine or the distance over which the force is applied

6 0

2 years ago

a bicyclist travels with an averahe velocity of 15km/h north, for 20 minutes .what is his displacement ?

Lunna [17]

Explanation:

velocity = 15 km/hr = 15×1000m / 60×60s

= 4.17 m/s

time= 20 min= 20 × 60s

= 1200s

displacement =?

we know that,

V = D / t

or, 4.17 = D / 1200

or, D = 4.17 × 1200

or,D = 5004 m

7 0

3 years ago