A Truck with a mass of 1500 kg is decelerated At a rate of 5m/s2. how much force did this require

A pear hangs in a tree at a height of 1.8 m. The pear has a mass of 0.2 kg. The pear falls out of the tree and lands on the grou

TiliK225 [7]

a) PE=mgh=0.2*9.8*1.2=2.352 J

b) KE=PE=2.352 J

c) $v=\sqrt{\frac{2KE}{m}}=4.85$ m/s

6 0

3 years ago

When exposed to a radioactive source which emits 1.2-MeV gamma-rays, a particular material is found to have a half-value thickne

iren2701 [21]

Answer:E

Explanation:

It is given that Energy of gamma ray is E=1.2 Mev

Shielding effect can be measured by measuring the fraction of gamma rays blocked by shield. If certain thickness will able to block half the radiation then to block 75% radiation we need to add same amount of thickness in order to block the remaining radiation.

i.e. $\frac{E}{2}$ fraction is blocked by 10 cm thickness

then remaining radiation is $\frac{E}{2}$

another 10 cm thickness will block the remaining half radiation i.e. $\frac{1}{2}\times \frac{E}{2}=\frac{E}{4}$

so total 75 % radiation will be blocked

4 0

2 years ago

A solenoid 50-cm long with a radius of 5.0 cm has 800 turns. You find that it carries a current of 10 A. The magnetic flux throu

ioda

Answer:

126 mWb

Explanation:

Given that:

length (L) = 50 cm = 0.5 m, radius (r) = 5 cm = 0.05 m, current (I) = 10 A, number of turns (N) = 800 turns.

We assume that the magnetic field in the solenoid is constant.

The magnetic flux is given as:

$\phi_m=NBAcos(\theta)\\Where\ B\ is\ the\ magnetic\ field\ density,A\ is \ the\ area.\\But\ B =\mu_onI.\ n \ is\ the\ number\ of\ turns\ per\ unit \ length=N/L\\Therefore,B=\frac{\mu_oNI}{L} \\substituting\ the\ value\ of\ B\ in\ the\ equation: \\\phi_m=\frac{NAcos(\theta)*\mu_oNI}{L} .\ But \ \theta=0,cos(\theta)=1\ and\ A=\pi r^2\\ \phi_m=\frac{N^2\pi r^2\mu_oI}{L} \\Substituting\ values:\\\phi_m=\frac{800^2*(\pi*0.05^2)*(4\pi*10^{-7})*10}{0.5}=0.126\ Wb=126\ mWb$

8 0

3 years ago

When a 12 V battery is connected across an unknown resistor, there is a current of 2.5 mA in the circuit. Find the value of the

nataly862011 [7]

Answer:

Given: V=12 V

I=2.5 mA

Let the resistance be R

By Ohm's Law,

V=IR

12=2.5×10−3R

R=4.8×103 Ω

8 0

2 years ago

An apprentice bricklayer stabs 30cm long blocks on top of each other in such a way that 5cm of each block hangs over the lower b

NikAS [45]

Answer:

Explanation:The work done is twice as great for block B because it is moved twice the ... Equal forces are used to move blocks A and B across the floor. ... Does the normal force of the floor pushing upward on the block do any work? ... Suppose that the mass is halfway between one of the extreme points of its motion and the center point.

7 0

2 years ago