Power(p) = 2kW
Time(t)= 3 h
Work done(w) = ?
p = w / t
w = p × t
w = 2kW × 3 h
w = 6kWh
Converting 6kWh to Joules,
6kWh
6×(10^3)h ( k = 10^3 )
6×10^3×(60×60) ( 1 hour = 60 × 60 sec)
2.2×10^7 J in 2 significant figures
If a constant force is applied on a body, the body moves with constant acceleration.
Answer:
a) The velocity of rock at 1 second, v = 9.8 m/s
b) The velocity of rock at 3 second, v = 29.4 m/s
c) The velocity of rock at 5.5 second, v = 53.9 m/s
Explanation:
Given data,
The rock is dropped from a bridge.
The initial velocity of the rock, u = 0
a) The velocity of rock at 1 second,
Using the first equation of motion
v = u + gt
v = 0 + 9.8 x 1
v = 9.8 m/s
b) The velocity of rock at 3 second,
v = u + gt
v = 0 + 9.8 x 3
v = 29.4 m/s
c) The velocity of rock at 5.5 second,
v = u + gt
v = 0 + 9.8 x 5.5
v = 53.9 m/s
Most of the elements are metals
