Answer:
By conservation of energy, it can climb up to a height equal to that it went down before. However, due to the friction in the machines, the total mechanical energy of the roller coaster will decrease. As a result, the first "hill" of many roller coasters are the highest, but the followings will have decreasing heights.
Explanation:
the rate of work done or doing work is usually measured by the power of a machine .
D. The molecules in water are constantly moving.
They are able to do this because they move around to take whatever shape of the container.
Answer:
970.2 N
Explanation:
We are given that
Length of ladder=2.7 m
Mass,M=11 kg
Coefficient of friction=

Mass of painter=8M
Distance from base=d
We have to find the magnitude of the normal force exerted by the floor on the ladder.
Normal force exerted by floor on the ladder=
Where 
Normal force exerted by floor on the ladder=
Answer:
c) It increases by a factor of 8
Explanation:
According to Faraday's law (and Lenz' law), the induced EMF is given as the rate of change of magnetic flux.
Mathematically:
V = -dФ/dt
Magnetic flux, Ф, is given as:
Ф = BA
where B = magnetic field strength and A = Area of object
Hence, induced EMF becomes:
V = -d(BA)/dt or -BA/t
If the magnetic field is increased by a factor of 4, (
) and the time required for the rod to move is decreased by a factor of 2 (
), the induced EMF becomes:


The EMF has increased by a factor of 8.