Answer:
when the radius is halved, F becomes 4 times
Explanation:
<u><em>The formula is given by</em></u>

<u><em>When r is halved:</em></u>

=> 
=> 
<u><em>This means when the radius is halved, F becomes 4 times</em></u>
For idea gases, volume is directly proportional to temperature. That is, an increase in temperature leads to increase in volume and vice versa.
Therefore,
V1/T1 = V2/T2 => T2 = (V2*T1)/V1
Assuming that the balloon is spherical in shape,
V= 4/3*pi*R^3.... In the formula for calculating T2, 4/3*pi cancels out.
R1 = 30/2 15 cm; R2 = 30.5/2 = 15.25 cm; T1 = 20+273.15 =293.15 K
Therefore,
T2 = (R2^3*T1)/R1^3 = (15.25^3*293.15)/15^3 = 308.05 K = 34.9 °C
V o - initial velocity
v = velocity at the maximum height,
v² = v o² - 2 g h
v = 0
0 = v o² - 2 g h
v o² = 2 g h = 2 · 9.80 · 0.460
v o² = 9.052
v o = √9.052 = 3.004197 m/s ≈ 3 m/s
Answer:
25 m/s
Explanation:
This question can be solved using equation of motion

where
v is the final velocity
u is the initial velocity
s is the distance covered while moving from initial to final velocity
a is the acceleration
_____________________________________________
Given
box moved for distance of 62.5 m
Friction slows the box at –5.0 m/s2----> this statement means that there is deceleration , speed of truck decreases by 5 m/s in every second until the box comes to rest. Friction causes this deceleration.
thus in this problem
a = -5.0 m/s2
V = 0 as body came to rest due to friction deceleration
u the initial velocity we have to find
the initial velocity of box will be the same as speed of truck, as the box was in the truck and hence box will pick the speed of truck.
so if we find speed of box, we will be able get sped of truck as well.
using equation of motion

Thus, initial speed with the truck was travelling was 25 m/s.
When the ruler is broughı near the inetal knob, it repels electrons in the metal. Electrons move away froni the ruler and down the metal rod. The knob now has a positive charge. The thin pieces of metal foil at the bottom of the metal rod now have a negative charge.