Answer:
acceleration, a = 9.8 m/s²
Explanation:
'A ball is dropped from the top of a building' indicates that the initial velocity of the ball is zero.
u = 0 m/s
After 2 seconds, velocity of the ball is 19.6 m/s.
t = 2s, v = 19.6 m/s
Using
v = u + at
19.6 = 0 + 2a
a = 9.8 m/s²
The formula for velocity is distance divided by time, or d/t. The distance is 500 km and the time is 1.2 hours. 500/1.2 is 416.6 km/hr.
The lines can be traced out with a compass. The needle is like a permanent magnet and the north indicator is the north end of a magnet.
Data is inappropriate
here, we need gauge of the wire i.e., diameter of the wire, so that we calculate the resistance by using the formula
R = ρl/A
where R= resistance ; Ω
l = length of wire ; m
A = area of wire ; m²
ρ = resistivity ; Ω-m
But in general ohms law is
V = I R
R = V/I ;
but here we also calculate "R" from length of wire in which the current is flowing.
I hope it is helpful to you.
A distance of 10.8 cm beyond its natural length will a force of 30 N keep this spring stretched
<u>Explanation:</u>
Work, W = 2 J
Initial distance,
= 30 cm
Final distance, = 42 cm
Force, F = 30 N
Stretched length, x = ?
We know,
W = 1/2 kΔx²
Δx = 42-30 cm = 12 cm = 0.12 m
2 J = 1/2 k X (0.12)²
k = 277.77 N/m
According to Hooke's law,
F = kx
30 N = 277.77 X x
x = 0.108 m
x = 10.8 cm
A distance of 10.8 cm beyond its natural length will a force of 30 N keep this spring stretched.