<span>Correct Answer: Option B
The complete question is:
A train starts from rest and accelerates uniformly until it has traveled 3.7 km and acquired a velocity of 30m/s The train then moves at a constant velocity of 30m/s for 410 s. The train then slows down uniformly at 0.065m/s</span>²<span> until it reaches a halt. What distance does the train travel while it is slowing down?
We have the initial velocity u = 30 m/s
Final velocity = v = 0
Acceleration = a = -0.065 m/s</span>²
The negative sign indicates that the train is slowing down.
Using the 3rd equation of motion, we can find the distance covered by the train:
2as = v² - u²
2(-0.065)S = 0 -30²
⇒
S = 6923 meters = 6.9 km
Answer:
increase
Explanation:
According to Einstein's photoelectric equation; the energy of a photon striking a metal surface is related to the kinetic energy of the ejected photoelectron by the formula;
KE= hf - hfo
Where h is the planks constant, f and fo refer to the frequency of incident photon and the threshold frequency respectively.
Hence, we can clearly see from the foregoing that the kinetic energy of the ejected photoelectron is proportional to the frequency of the incident photon.
Hence, if the frequency of the incident photon is increased, the kinetic energy of the ejected photoelectron increases also.
Answer:
Explanation:
Height attained by body = 50 cm
= .5 m
Initial velocity = u
v² = u² - 2gh
0 = u² - 2gh
u² = 2 x 9.8 x .5
u = 3.13 m /s
During the initial period , the muscle stretches by around 10 cm during which force by ground reacts on the body and gives acceleration to achieve velocity of 3.13 m/s from zero .
v² = u² + 2as
3.13² = 0 + 2 a x .10
a = 49 m/s²
reaction by ground R
Net force
R-mg = ma
R= m ( g +a )
= mg + ma
=W + (W/g) x a
W ( 1 + a / g )
= W ( 1 + 49 / 9.8 )
= 6W
I don't see a table anywhere near here, but I think I can show you how to calculate those quantities.
From your description, I'm picturing two 32-ohm resistors in parallel, connected across a 96-volt battery or other power supply.
In parallel, each resistor has the same voltage across it. So it might be easier
if we begin by considering them separately:
Current through one resistor = V/R = 96/32 = 3 Amperes.
Current through both of them, supplied by the battery = <em>6 Amperes</em>.
Power dissipated by one resistor = I² R = (3)² (32) = 9 x 32 = 288 watts.
Power dissipated by both of them, supplied by the battery = <em>576 watts</em>.
Equivalent resistance as seen by the battery = (32)² / 64 = <em>16 ohms</em>.
<u>Check:</u>
If the battery sees 16 ohms, then the current is V/R = 96/16 = <em>6 Amp</em>.
Power supplied by the battery is (V x I) = 96 x 6 = <em>576 watts</em>.
yay !
<u>Note:</u>
288 watts is a lot of power. You'll need big, expensive resistors,
possibly even immersed in an oil bath, unless your resistors are
coils of resistive wire and you plan on toasting bread with them.
Answer:
yes
Explanation:
when we throw a ball upwards, it will eventually come back to us because of force.