Answer:
W = 7000 J
Explanation:
To solve this problem we use that the speed of the bicycle is constant, therefore its acceleration is zero
F -fr = 0
F = fr
where F is the force applied by the child
Work is defined by
W = F. x
W = F x cos θ
in this case the child's force is parallel to the movement, therefore the angle is zero and cos 0 = 1
let's calculate
W = 35 200
W = 7000 J
Find the intensity of the electromagnetic wave described in each case.
(a) an electromagnetic wave with a wavelength of 645 nm and a peak electric field magnitude of 8.5 V/m.
(b) an electromagnetic wave with an angular frequency of 6.3 ✕ 1018 rad/s and a peak magnetic field magnitude of 10−10 T.
Answer:
- Water gained: 10
- Iron lost: -10
Explanation:
Given: Hot iron bar is placed 100ml 22C water, the water temperature rises to 32C
To find: How much heat the water gain, how much heat did the iron bar lost
Formula:Q = change T x C x M
Solve:
<u>How much heat water gained</u>
Initial heat = 22, then rose to 32. To find how much heat the water gained, simply subtract the current heat by the initial heat.
32 - 22 = 10
The water gained 10 amounts of heat.
<u>How much heat Iron lost</u>
Current heat = 32, then dropped to 22. To find how much heat the Iron lost, simply subtract the initial heat by the current heat.
22 - 32 = -10
The Iron lost -10 amounts of water.