B. +Q, + W are the correct sign
The car at 60 kph has 9 times more kinetic energy than the car traveling at 20 kph. This assumes that both cars have the same mass. Kinetic energy depends on the square of thee speed so if one car is going 3 times faster, its kinetic energy will be 3^2 ( = 9 ) greater. The car going at 60 kph will have 4 times the KE of the car going at 30 kph ( again assuming that the cars have the same mass.)
It doesn't matter what the object's initial velocity is, or how long
the acceleration lasts. All that matters is the object's mass and
acceleration.
Force = (mass) x (acceleration) =
(5kg) x (15 m/s²) =
75 kg-m/s² = <em>75 newtons .</em>
Answer:
Explanation:
Let acceleration of fall be a .
v² = u² + 2as
v = 3.8 m /s
u = 0
s = 3.5 m
3.8² = 0 + 2 x a x 3.5
a = 2.06 m /s²
Since this acceleration is less than g , an upward force is acting on the firefighter in the form of friction . Let this force be F . Let mass of the firefighter be m .
m = 765 / 9.8
= 78.06 kg
mg - F = ma
765 - F = 78.06 x 2.06
765 - F = 160.8
F = 604.2 N .
Answer:
At the surface of the Atlantic Ocean
Explanation:
The atlantic ocean is a worm ocean and the surface has the least dense water. This is because the denser layer of water sinks, while the least dense floats.
The Atlantic Ocean stands out in the choices with warmer temperatures at depths. This results from the different flow dynamics in the semi-enclosed Mediterranean Sea.
