Explanation:
Acceleration is the rate of change of velocity with time. When acceleration increases a body moves a faster velocity.
- In the graph acceleration at time t= 100s is rapidly increasing.
- At t = 20s, the acceleration of the body is getting started up.
A vehicle at time 100s will have a faster velocity compared to one at t = 20s
Answer:
6.13 s
219 N
Explanation:
Newton's law in the x direction:
∑F = ma
150 cos 30° N − 50 N = (30 kg) a
a = 2.66 m/s²
Δx = v₀ t + ½ at²
(50 m) = (0 m/s) t + ½ (2.66 m/s²) t²
t = 6.13 s
Newton's law in the y direction:
∑F = ma
Fn + 150 sin 30° N − (30 kg) (9.8 m/s²) = 0
Fn = 219 N
The use of pesticides in farming land is example of non-point source pollution. The area of emitting of pollution is very large. That is why, it is difficult to monitor and control this type of pollution.
Americans get their water for everyday use through aquifer. Aquifers can be conserve by avoiding high amount of chemical uses and reducing household waste. Also the sustainable use of water cause conservation of natural resource.
Aquifer are basically underground water present in ground pores. The structure of aquifer just look like sponge. The water moves through the porous surfaces of the ground.
Answer:
D. Tidal energy is replaced naturally by the Moon's gravity.
Explanation:
The reason tidal energy is considered a renewable energy resource is that Tidal energy is replaced naturally by the Moon's gravity. The Moon's gravity creates bulges on the side of Earth that is closest and farthest from the Moon. These bulges also pull water causing high tides in those areas. As the Earth rotates these areas experience low tide while the areas that had low tide now experience high tide. This constant shift creates tidal energy every day, which is replenished naturally.
The viscous force on an object moving through air is proportional to its velocity.
The only forces acting on an object when falling are air resistance and its weight itself. The weight acts vertically downwards whereas air resistance acts vertically upward.
Let F be the viscous force due to air molecules, B be buoyant force due to air and W be the weight of falling object. Initially, the velocity of falling object and hence the viscous force F is zero and the object is accelerated due to force
(W-B). Because of the acceleration the velocity increases and accordingly the viscous force also increases. At a certain instant, the viscous force becomes equal to W-B. The net force then becomes zero and the object falls with constant velocity. This constant velocity is called terminal velocity.
Thus at terminal velocity, air resistance and force of gravity becomes equal.
