All categories

3 years ago

A ball is suspended by a lightweight string, as shown in the figure above.

Physics

2 answers:

KatRina [158]3 years ago

7 0

The answer is C: 3 and 4
proof:
the greatest value of the speed is on the number 4,
V1<V2<V3<V4; but we know that if the speed is higher, so is kinetic energy value. V4 is the speed having higher value (between 3 and 4)

Irina18 [472]3 years ago

6 0

Answer

A. 1 and 2

Explanation

At point 1 we have the highest potential energy and the kinetic energy is zero.

At 2 the potential energy is minimum and the kinetic energy is maximum.

The law of conservation of energy says that energy cannot be created nor destroyed. So, the change in P.E = Change in K.E.

P.E = height × gravity × mass. The height referred here is the perpendicular height. Gravity and mass are constant in this case.

From the diagram it can be seen clearly that the vertical height from 2 to 1 is much greater than from 4 to 3.

This shows that the change in P.E is greater between 1 and 2 and so is kinetic energy.

You might be interested in

PLEASE HELP!!! THIS IS URGENT

aniked [119]

It's 120N downwards. net force is adding or subtracting the x and y values

5 0

3 years ago

Read 2 more answers

I believe Newton's 1st law is

Bogdan [553]

Answer:

The first law states that if the net force is zero, then the velocity of the object is constant.

5 0

3 years ago

a car is moving with a constant speed of 20 meters per second.What total distance does the car travel in 2 minutes

N76 [4]

There are 120 seconds in two minutes, so to find the answer, you multiply 20 x 120 to get 2400 meters.

8 0

3 years ago

Suppose a large power plant generates electricity at 12.0 kV. Its old transformer once converted this voltage to 315 kV. The sec

SpyIntel [72]

Answer:

2.32
0.43

Explanation:

12.0 kv primary voltage

315 kv secondary voltage ( converted voltage ) V1 or Vo

v2 (Vn)= 730 kv new secondary voltage

a) Ratio of turns in 730 kv to turns in 315 kv

$\frac{Vn}{Vo} = \frac{Nn}{No}$ = $\frac{730}{315}$ therefore the ratio of turns = 2.317 ≈ 2.32

B) ratio of the new current output to the old current output for the same power input to the transformer

since the power input is the same

$\frac{In}{Io} = \frac{\frac{Vp}{Vn} }{\frac{Vp}{Vo} }$ equation 1

Vp = primary voltage, Vo = old secondary voltage, Vn = new secondary voltage, In = new secondary current, Io = old secondary current

therefore equation 1 becomes

$\frac{In}{Io} = \frac{Vo}{Vn}$ = 315 / 730 = 0.43

7 0

3 years ago

An all-electric car (not a hybrid) is designed to run from a bank of 12.0 V batteries with total energy storage of 2.30 ✕ 107 J.

AnnyKZ [126]

Answer:

a) $I=733.33\ A$

b) $d=52272.7273\ m$

c) $d'=51948.0519\ m$

Explanation:

Given:

voltage of the battery, $V=12\ V$

energy storage capacity of the battery, $E=2.3\times 10^7\ J$

speed of the car, $v=20\ m.s^{-1}$

power drawn by the car, $P=8.8\ kW$

Now the Current delivered to the motor:

we the relation between the power and electrical current,

$P=V.I$

$8800=12\times I$

$I=733.33\ A$

Distance travelled before battery is out of juice:

we first find the time before the battery runs out,

$t=\frac{E}{P}$

$t=\frac{2.3\times 10^7}{8800}$

$t=2613.636\ s$

Now the distance:

$d=v.t$

$d=20\times 2613.636$

$d=52272.7273\ m$

When the head light of 55 W power is kept on while moving then the power consumption of the car is:

$P'=P+55$

$P'=8800+55$

$P'=8855\ W$

Now the time of operation of the car:

$t'=\frac{E}{P'}$

$t'=\frac{2.3\times 10^7}{8855}$

$t'=2597.4026\ s$

Now the distance travelled:

$d'=v.t'$

$d'=20\times 2597.4025$

$d'=51948.0519\ m$

5 0

3 years ago